I have a pure lone wolf rogue, and he does just fine. The extra recovery AP and vitality bonus are very useful, the important thing being that it allows me to (somewhat) safely ignore con as a stat.
You'll want to decide if you want to be lone wolf or not, and foremost a dagger or bow user (there is a lot of room for switching around however). If you want to be a bow main, you'll probably want to pick up some points in perception. If you do, you might want the character to be the dedicated trap spotter.
With my build, I've actually started using a bow half of the time now against CCed (but not frozen) enemies. My mages control the field, and if there is too much fire or poison I don't want to 'get my hands dirty'. I put most points into dex (13 maybe) and I think 7 base speed at level 16. 1 Con from the (single) non-cheaty book.
The scoundrel 'offensive' skills include very good CC. But you need a dagger equipped to use them. The problem with a dagger user is in staying alive (if you aren't going to use sneak invincibility at the end of every turn). I imagine without lone wolf, my rogue would have a hard time, but then again I'd have another character (and maybe summon) for the enemy to hit/use CC on.
What you really need to do is work out a team strategy you think will work. I built my team with the idea of my mage/jahan CCing enemies and buffing the rogue to allow him to kill everything, and it works incredibly well. Anything you want to do will probably work. Examples off the top of my head include:
your thief as the damage dealer (backstab or quickdraw, maybe bully) with support from other team members
dagger thief spamming CC on the enemy (there's a charm (2 with rapture from marksman, which is just better), trip, stun, blind, poison, bleed) without really doing much damage.
using special arrows along with your other characters to set off combos.
creating summons and using charm with the 'thief' to sow disarray into the enemy ranks.
Off-topic: I really would like a talent that removes the AP cost for switching weapons. It would make pure dex characters less 'underpowered' I feel.
Don't worry about ability points put into nasty deeds. I have 3 wasted weapon points, high bb/wp and 6 points in sneak which I rarely use. Your build will be more streamlined than many in terms of skills.
