With all due respect to Jake, I don't like the drow crafter build for the simple reason that a LOT of the spells you need are clerical or druidical in nature.
The second reason is that the ECL rating of the drow means you will likely fall two levels short of the level 20 cap. My Aasimar paladin is likely going to cap at level 19 and i have done every quest. Sun elf would avoid the ECL penalty at least.
Taking a level of cleric won't solve your problem though. A single level of cleric would have a caster level of ONE when casting clerical spells. You do NOT add all spell caster levels to determine caster level. A mage 10 / cleric 10 would have a caster level of 10 for either spell class.
I also don't like diluting other skill categories just to pump up crafting skills but then with a paladin I could only afford points in three skills, and I would definitely recommend having a high diplomacy skill and a fairly high appraise skill for starters. I think Jake might delay some skill points for cross-class skill reasons but I'm not sure.
IIRC almost all of the caster NPCs (Elanee, sand, Qara, Zhjaeve and even Ammon Jerro) have very good alchemy skills so putting points in them isn't really necessary but a single point can be useful. (Will explain this later).
Sand and Khelgar make great armor and weapon crafters so that should be coveered in game terms.
As for traps, i usually have Neeshka along so she covers them for me - but otherwise have her pickpocket the Chime of opening from one of the merchants in the docks, use that to open the chests, and just take your chances with the traps. hehehe
Okay, let's go back to the skill points. With a headband of intellect +8, Grobnar's inspire confidence song (+4 to skills at level 11) and the gloves of the artificier bought from Nya in port LLast in chapter 3, you will end up with at least +14 to all your crafting skills - and that doesn't count your own intelligence score modifiers! So even with just a point or two in craft alchemy you will be able to distill every essence in the game (max skill is a 10) and even do the merges to upgrade (max skill 15). Aside from the daragon hide half plate, the next highest crafting skill needed is a 23 for admantine full plate or an adamantine exotic weapon. With 14 points in boosts, you're over half way there. 10 points each in craft armor and craft weapon will get you anything you need, and you can actually do almost all of the basic crafting yourself and let the spellcasters do the heavy enchanting.
I still prefer having the NPC's do the crafting and enchanting but it's not necessary to shove as many points as Jake suggests in as long as Grobnar is around.