]Not necessary is not the same thing as not useful. While I do think shields are relatively important for "mono" Str builds, I think Shield Specialization is an invaluable tool for Str/Int hybrid builds; in other words, shields are for Clerics. This has a lot to do with how hybrids have trouble adding Constitution.
Shields can also be useful on mage characters who want to boost their elemental resistances up higher, such as a mage who likes to fireball himself or cast storm frequently. But you don't actually need to put a single point into Shield Specialization to make it through the game just fine.
This assumes you're not powergaming the hell out of Teller of Tales starting at a very low level. If you aren't, then you're right. If you are, then it's really hard to spend that amount on books every level and not go broke.
Buying more than one set of books was supposed to be removed in the previous patch. It was not, so you may want to plan for it to be removed in the next patch.
It doesn't always work this way. There are even NPCs where you don't get a chance to play RPS at all unless you meet a minimum Charisma score.
It works that way in an overwhelming majority of cases, so unless you are specifically hunting fringe cases or they introduce more in the future, you may not even notice the difference.
This assumes your time isn't valuable, because swapping people out at the Hall every time you craft makes crafting even more of a tedium. If you want to save time, you don't segment things off like that. With +Crafting and +Blacksmithing items, the ability point investment is meager anyway (2 hard points in each for 6 ability points total, assuming Scientist talent; less if Pragmatic trait).
I just tried it, it takes less time to swap out to a fully crafting ready henchman and hand him the latest crafting supplies than it does to change into your crafting gear and be handed the latest crafting supplies. It's also less RNG reliant, and can be accomplished earlier in the game.
Not to mention whatever time you save killing enemies faster and/or not having to replay fights.
