It's certainly not going to increase the power of the rogue class, given that you follow the rules that say you can't take any given talent more than once unless otherwise specified. Most likely it's going to prevent that rogue from being much use at all in combat.
"Well, I was wondering if you'd allow a slight variant on Rogue. You see, I don't care about Sneak Attack, but I do like the look of the talents. I was wondering if I could do away with the former to have a few more of the latter?"
This question was raised by one of my freinds, who will be joining my campaign this sunday. What would be fair in this case, a rogue talent instead of a increased to sneak attack and the normal talent progression?
My first thought was, 'sounds like it would be wimpy'.
Then I remembered, you can take a feat for every talent after 10th level. Which means you could get a feat every level from 10 to 20.
That's VERY powerful. However, does it make up for losing Sneak Attack? I guess it really just depends on how many splat books you're allowing feats to be taken from. It's probably not overpowered, and if he builds it right, it could be balanced.