Making arcane trickster work [PF only]

[Carth]

I'm entertaining going wizard5/rogue1/assassin1/arcane trickster10/something3

However, do arcane tricksters function well in PF? What are good spells to sneak attack with, given that we'll be using the ruling that scorching ray and similar spells can get sneak attack damage on each attack roll? Telekinesis looks to be cited as having potential for abuse, but it looks like it'd take so much setup to get that to work that it's not a real consideration by the time it comes online. I'd be starting at level 1 and going up to or near level 20.

[Occasional Sage]

Why not Magus, if you're looking for spell sneak attacks? Using Spellstrike to borrow your weapon's crit range while sneak attacking with blade and magic = win. If you take Magus to 6 you can add the Prescient Attack arcana to deny Dex bonuses for more SA goodness.

[StreamOfTheSky]

OP, I think you mean Wizard 4 into AT, not Wiz 5...

In any case [sneak attack base class] 1 + [sneak attack PrC ] 1 + Wiz 4 is the strongest entry in general, since you lose the fewest CL that way.

I would use Vivisectionist Mindchemist Alchemist (possibly add Internal archetype as well, depending on how much you care about splash weapons) instead of rogue. It is a much stronger class. Gives good fort and reflex, some extracts, and most importantly the cognatogen, for a temporary +4 Int buff that will stack with everything. Oh, and double Int on all knowledge checks.

For the PrC, assassin works, but is evil and pretty mediocre. The Sleepless Detective will also give you the +1d6 SA and gives you Int to Perception and some other skills, and might be a better fit. Sadly, both require 5 levels elsewhere first (otherwise you could just do wiz 3 / SA base class 1 / SA PrC 1), there is no +1d6 SA PrC in PF you can enter at 5th level as far as I know.

Now, I do also like just straight up Viv. MC Internal Alchemist 3 / Wiz 3. You lose another CL, but now have a discovery and acess to the Extra Discovery feat, as well as the cognatogen working 30 min instead of just 10.

As for spells to sneak attack with... I assume the Telekinesis suggestion was based on throwing a ton of weapons and getting SA on all of them? That is certainly a strong choice. Note that in PF, the "volley rule" from 3E C.Arcane never made it over in the transition. By RAW in PF, you get SA on every attack a spell grants. So any spell that gives you a lot of ray attacks all at once is a good choice.
When you hit AT 10, the best new options, IMO, are Magic Missile and Stone Call (http://www.d20pfsrd.com/magic/all-spells/s/stone-call). Both are unavoidable. MM is lower level, Stone Call hits a huge radius, allows not even SR (never mind a save!), and also leaves behind difficult terrain. Oh, and stone call with the Merciful (http://www.d20pfsrd.com/feats/metamagic-feats/merciful-spell-metamagic) meta feat applied could also be (hypothetically) combined with Sap Adept (http://www.d20pfsrd.com/feats/combat-feats/sap-adept-combat) and Sap Master (http://www.d20pfsrd.com/feats/combat-feats/sap-master-combat), as it is now dealing nonlethal bludgeoning damage. So yeah, Stone Call is pretty freaking awesome for level 10 Arcane Tricksters.

Is AT worth it in PF? The low and mid levels will be very painful, once you're deep into AT I think it does pay off in the long run ...as long as you calibrate your expectations to be between a wizard and rogue-type in power, and not equal to Wizard 20. I would not bother playing an AT in a game that started at low levels (like, below 4 or 5), nor in a game where reaching AT 10 and playing for a while afterwards is not expected to happen.
Be sure to buy or craft Sniper Goggles to synergize your ability to sneak attack with your ability to cast spells from far, far away.