Ive made a mage and picked up 3 elemental skills, air, geo and pyro. Is this too much? is it impossible to get the high level spells doing it this way?

Not too much. Not impossible to get the high level skills. You're fine.

In regards to learning multiple schools of magic you should know that later in the game you will be able to trade 1 unspent talent point for 10 ability points. If you can't find a talent that interest you it might be an idea to just save the talent point for a later trade.

Theres not many talents you really NEED.

For combat characters you only really want.
1) Bully.
1) Lone Wolf.
5) Glass Cannon
7) Expert Marksman OR Weather The Storm.

For mages you only really want.

1) Pet Pal.
1) Lone Wolf.
5) Glass Cannon.
7) Far Out Man.

You can easily turn the other talent points into Ability Points and pump your Body Building/Willpower.

Not having enough ranks in a skill tree for a particular spell only means that you have to pay an extra 2 AP for each rank you are missing.
There is only 1 spell per mage tree that requires rank 5, so if you are OK paying 2 extra AP for those you can get 3 trees to level 4 without investing additional points.
My recommendation is to bring all 5 trees to level 1-2 first instead of focusing at leveling 1 as fast as possible.

Lone Wolf is crap. Seriously. You get +2 AP (which you then double to +4). But you lose, at a minimum, 6AP which would be on the companion (more realistically 12AP, because Glass Cannon). Plus 4, minus 12 is a crappy trade, especially since it actually costs a talent. The best way to describe Lone Wolf is that you take Glass Cannon's effect and invert it; Lone Wolf should be called Antimatter Cannon or something. And since Glass Cannon is the best thing ever, Lone Wolf is the worst thing ever.

The talent does other things too, but if you think AP isn't the most important thing in the game, you're kidding yourself.

You get plenty of ability points. Use at least three of them to get Man-at-Arms 2 (potentially more) and snag Picture of Health. On everyone. That should be enough extra Vitality to get Glass Cannon on everyone, even on Hard difficulty.

2 Gods are way better than 4 mortals

...and 4x Glass Cannon is 4 gods, which is better than 2.

I think the additional skill points are very good, too, and the vitality bonus compensates the vitality reduction of glass cannon. The additional vitality points of the overpowered elemental shields are based on the current vitality points of the target and this makes lone wolf very useful, too.

If you do however wish to play with only your two starting characters then the reduction in AP is already in play and the gain in ability points, action points and health comes without additional cost as you wouldn't have the other characters actions anyways.

2 toons with 9 willpower and 9 bodybuiding are way better than 4 with 6 of each.

If all you care about is becoming indestructible, then take lone wolf.
If you care about dealing damage, then don't take lone wolf.

Lone wolf parties deal way less damage, since they're effectively trading an entire other character for a measly 2AP per turn.
The 80% increase to HP, and the extra Ability points can definitely wind up making the characters tankier, but this will not be an issue for you at endgame regardless.

That said, I'm currently running with a lone wolf because I wanted to cut down on my party size (and test a potential exploit later on).

realistically you will never need more than a 3 in most spell schools.

also, due to resists, you will generally want a mage type to be an 'elementalist' and at least have basic options to deal with various enemy resistances.

personally i would go with a 3, maybe a 4 if really needed, in all 4 elements then at least 2 loremaster boosted to 5 with gear so you can see enemy resists. you can do this for around 40 of your skill points. with lone wolf and no books you end up with about 68 points, so very feasible.

if you really want those end-game spells, and most suck, just deal with 2AP penalty on cast. you can use them at most once per fight and with glass cannon you will be ok.

That's not entirely true. Lone Wolf grants additional Ability Points, which allow a single character to stack excellent offense and defense, and allow talent and spell combos that are completely impossible across a single character without book exploiting. It also much easier to keep the inventory of two characters clean than four characters, and if you are going to only play with two characters anyway because it is dramatically less hassle, you might as well take Lone Wolf.

But generally, I do agree that Lone Wolf is a difficulty INCREASE.

If I were you I'd only raise those skill up to level 4. You can't learn all spells this way, but in my opinion a lot of spells aren't that useful anyway. And you'll have a small penalty when casting high level spells, but those (Hailstorm, Earthquake and Meteor Shower) aren't worth it either.

I have an all-round LWGC Mage specced in every magic school. Gets shit done and feels good. High-lvl spells included. Never regretted the decision to spec her so.

One thing I forgot to mention earlier: Moloch will offer you ten ability points in exchange for one talent point. Ten's quite a bit, fully half of the "ability-point" part of LW, but without the drawbacks. If you're hurting for ability points, that's the way to get them.

Ditto. My caster currently has 5 in two magic schools and 3 in all the rest, without neglecting defensive skills.

I really don't feel like having two characters is gimping me in any way. In fact, sometimes I wish I could play with one character. Half the time, my melee fighter's standing around watching the fireworks. I probably should have started raising her INT and giving her a magical school or two to play with.

The only 2 skill sets I don't have on my mage is Scoundrel and Marksman, and it kicks very serious ass.

I am going to be making a guide for my mage to explain this.

If you add 1 point in Marksman you can get Tactical Retreat, First Aid and Doctor (although +2AP cost on Doctor)

The real benefit of Lone Wolf is in the extra ability points it grants. Extra AP is OK, extra HP is good. However, at level 20, you'll have 20 extra ability points to spend, that's enough to max out one extra ability and take another one to level 2. And that's without having to sacrifice talent points and such.

Taking two Lone Wolves may be a problem because you'll have to spend at least some points in crafting (without crafting, you close some major income avenues to yourself at least). One LW plus one regular character lets you have a slave monkey for crafting, and a competent third for fighting. If all three characters take Witchcraft 3, you can summon three Armored Decapitators (INT does not matter for summons). Take Farsight and keep it up at all times so you can get the drop on most enemies. Summon the Decapitators close to your enemies and let them take the alpha strike. Then move in and go nuts with AoE. In my experience, the Decapitators are scary enough that they hold aggro as long as they are alive (even if they are frozen or knocked down). For more versatility, learn other summons in case the enemy happens to be weak vs. an element. If the summons die and you need a break, go invisible for a few turns (Walk in Shadows, Invisibility), wait for the summons to come off the cooldown, rinse and repeat. You'll never miss the fourth character.

You all talk about how taking lone wolf is wasting AP. True on paper but in a real fight, it's often the contrary. Why?

Because if your toon is not godly enough you will have to do all kind of stuffs: buffing, running, teleporting and cleansing etc... and waste tons of AP. Right now, either of my toons can wipe the entire group by just using battling ram. WW and DD are overkill.

In a long battle, that may not hold true anymore. However, if your fight only last one or two rounds then 4 toons are actually worse.

Edit: anyone knows how much ini the last boss has? I want to kill it in one round without letting it use a single ability.

Because of how my mage is built, those would be wasted skills.

Exactly, and I didn't feel like playing 4 characters with 1 action point each at all i'm also benefitting from a loss of WW, DD abilities and LW bonus level action points as I had to respec on lvl 13 or so. Still waiting for hotfixes.

Currently, due to a bug, one will lose all his extra Ability Points if he respecs at any point, even after reselecting Lone Wolf again. Thus, it is not retroactive. Unfortunately it's pretty much impossible for a totally new player to anticipate just what skills and abilities he'll want and how to build his character and even if he wants Lone Wolf (-ves) or not.

I can't agree that 2 LW is a problem, particularly when it comes to Crafting. I have all the roles neatly distributed between the two protagonists. And money is probably the last thing I worry about in the game as it gold literally rains down on player

I also have one my heroes playing all four elements. Because I'm the fucking Avatar! Spreading out my points among Intelligence, Constitution, and Speed (because Speed better AP bonuses than Perception). No Lone Wolf (..yet?). Mostly I just want the ability to cast two synergistic terrain spells (or synergistic status spells) in the order I want.