Thank you for your tips !
I totally agree with Pinpoint but why not take Arrow Recovery ? Is Scientist really usefull ?
For attributes, i was thinking of maxing Dex (increase arrow damage), and put the rest in Speed and Perception. Am I right ?
Do Bow/Crossbow abilities increase magic arrows damage ?
I do like the aeortheurge spell : Teleportation, it seems really interesting to place barrel or create group of enemy before throw a grenade. Or to use it with the Scoundrel bomb. But i'll need int to reduce the cooldown ? So is it really worth ? Maybe with LoneWolf ?
What's about Telekinesis ?
I didn't take Arrow recovery because this party is using Bairdotr as the primary ranger so she gets all the arrows. The Grenadier's bow is just a backup weapon. You can take Arrow Recovery if you want.
You do not want to take Scientist as a starting Talent for any reason. It adds one rank to those abilities, which means that if you take it when both Blacksmithing and Crafting are 0, it only gives you 2 Ability points worth. If you take them when they are both 1, it gives you 4 ability points worth, If you take them when both are 4 it gives you 10 ability points worth. Basically you want to take Scientist really late.
I do not believe (but am not certain) that bow/crossbow points improve magic arrow damage, I think that's fixed and the abilites just improve base weapon damage.
I guess Teleportation and Telekinesis are both okay for that build since it isn't very demanding points-wise. I can't say for sure I'm not that far into the game yet.
You'll never be able to reduce the cooldown for Teleport to lower than 4 turns less the default no matter how much INT you put in. It's probably not necessary to put it onto a Grenadier instead of a mage.