Not sweating out the UMD to get some wand use, being able to cast feather fall, shield, as well as armor early on...use a little vanish wand to get in some sneaks with acid blob or even take conjuration and get the acid dart..you get the idea. Take a 2nd level so you don't hamper the party at first and off you go. Wouldn't take the talent and such hits that arcane trickster does and you don't have to wait. I'm still not convinced the trickster is that helpful unless you have a foursome with two melee, one healer and you need some magical AND rogue backup. Comments?
The consensus in a recent thread is that the Arcane Trickster is a better rogue than a pure rogue. It has "Arcane Trickster" in the title. You might want to look into that before completely dismissing the AT. I have never played an AT so I can't really say much about it.
If you want to dip two levels just to get a little magic, I would suggest magus or bard rather than wizard. There are plenty of good archetypes for both that let you cast in light armor, get you nice weapon proficiencies, and/or improve your action economy. All things that can be good for a rogue.
There's the bookish rogue feat which helps flexibility a lot. Also think about a cloak of the hedge mage and similar utility casting items.
Half-elf racial trait lets you count as wizard for the purpose of spell trigger and spell completion items, if you make wizard your favored class. No dip neccessary.
Otherwise, consider the Counterfeight Mage archetype: Dex instead of CHA for Wands
Yeah I'm currently playing an AT through RotRL and its...rocky. Following the pointers in one of the available guides helps a lot. It may sound selfish but its more about helping the party by helping yourself. Splitting an admittedly class with another weak class to prestige into a medium power doesn't make you a terror in battle. But hitting the spellcaster from deep while invisible so you can add SA to a touch attack to ruin a spellcasters concentration check is always fun.
It's doable and advantageous as long as you realize you aren't ever going to be able to fulfill the God-caster role. Helped us out in RotRL because we didn't have a full arcane caster.
Magus! Of course....I had not ever really looked at that class but that is certainly looking like a winner. Tempting to take a few levels actually and get the Wand Wielder, but at least I would do one of the archetypes that lets you get a bonded item just for flexibility of casting..the Skirnir would allow you to have a buckler and still be a good ranged dexing rogue from what I'm seeing. Nice...the hit to the skills is a bit painful, but. GREAT suggestion!
And I will say the half elf wand etc. using feat is sweet, but I don't want to rely on that all the time-being able to do that acid blob at a high level while invis for sneak attack damage is perfection. Thanks all!
if you're just looking for a caster type with sneak attack, what about an alchemist, with the vivisectionist archetype? Sure, you're losing out on all the trap skills and such, but having an int heavy character means you'll keep all the skill points you'd lose by not being a rogue. Also, they maybe aren't all wand crazy, but .. elixirs. Same BAB as rogues. Also, discoveries that allow for some very versatile builds.
there's also investigator, which is very similar to alchemists, but not as sneak attacky. They can however do studied strike, which is like a sneak attack, but doesn't require the enemy to be flat footed or flanked. Unfortunately they can only do it once per enemy. In the meantime though, they get a flat attack/damage boost on whoever their studied target is. And they get all the same spell list as the alchemist.
Anyway, food for thought.
For defensive magic on a Rogue that wants to stay physical instead of going the trickster route, they could pick up Mirror Image through the Ki Pool and Ninja Trick: Shadow Clone talents. Then they can instead multiclass into something that helps combat ability...