Charisma is mostly useful for the rock paper scissor minigame. You should have a look at it first, and decide how you want to deal with this minigame (swap gear or not, save-scumm or not).
If you want to swap gear, you can craft up to 4 charisma items right off the bat.
Speed is best at odd number, and perception is best left even (best ignored actually, except for the explorer guy who has to spot traps and stuff, even though the spider invocation does a good job at finding stuff).
Attributes like INT, DEX and STR are varyingly interesting past 15 (STR is mostly not, DEX depends how often you use skills vs autoshots, INT depends if you use master spells often), gear included (I have between 10 and 12 without gear). But crafted gear usually requires high amount really quick, so it's usually the priority. Ideally, you want to start at 8 STR/INT/DEX at the start of the game, and then match this stat with the crafted gear requirement as you go along (and if you can/cannot find rings/necklaces/garments/belts that give bonuses - it's best to craft and switch items that give armor as frequently as possible).
You put extra points in speed or con, depending on your needs.
Having the craftman in your party requires 4 points (and attention to trait) if it's one of the two mains, or 6 if it's a companion, plus the scientist talent. You can swap character if you really want to optimize your build. Like the gear swapping for Charisma, it's up to you to see if the time lost is worth it (I think if you setup your craft camp in the armory as soon as possible it might be, but bear in mind you'll have to craft at every level up, or every two levels, to make at least the STR/DEX weapons and boost them with wetstone/bowcord + poison or tenebrium).
