Finalizing my character, but I can’t decide which skills to take to round out my planned build. I’m going (at least up through level 20) Wizard 17, Rogue 3 with Rogue taken at levels 1, 9 and 17. I can keep skills topped off through level 17 in Tumble, UMD, Search (stopping at 11 because of the INT bonus), Intimidate, Set Trap. Disable Trap, Concentrate, Spell Craft, Lore and Spot. Two skills I’m really missing here, at least in my early levels (later on I’ll have so much INT skills will be flowing out of my ears): Craft Trap and at least 6 in Craft Weapon for Craft Wand. Normally, I would dump intimidate for the more combat orientated skills, but I want at least one social skill, and I want intimidate for roleplay reasons.
I’m considering dropping Spot for Craft Weapon and Craft Trap. Is that a mistake? Or are there enough wands and traps to either buy, recovery or loot that I won’t miss the ability to craft them?
Almost all skills have at least occasional uses in Swordflight, so anything you take will be somewhat useful, but will also involve a trade-off as it means giving up another useful skill.
Tumble is probably the closest thing to a must have skill, so definitely max that out as much as you can. Concentration and Spellcraft are also crucial for a caster (Spellcraft in particular, in Swordflight, is used in a lot of special checks). Aside from that, you have a wide range of choices with trade-offs whatever you decide. There are definitely more uses for social skills in Swordflight than in most modules, so Intimidate is a reasonable investment.
Spot certainly is not that essential (especially considering that you will eventually be able to cast True Seeing spells to somewhat compensate for its absence), so it would certainly be reasonable to dump it for crafting skills if you think the latter would be more enjoyable to make use of or make more role-playing sense. However, keep in mind that with a big INT bonus, you can craft a lot of traps even without putting many actual points in the skill, so Craft Trap probably does not need to be a priority at low levels. You might want to also consider putting at least a few points into Open Locks and/or Pickpocket so as to be able to make at least limited use of those skills.
UMD is also less crucial for a Rogue/Wizard than it would be for a pure Rogue or Rogue/Warrior, since as a Wizard you can use most Wands and Scrolls (use of which being one of the main advantages of UMD) anyway. You can still get some use out of it, but it also a skill you could consider dropping, in this particular build, if you have too many other skills you want to develop.