I have a level 18 halfling swashbuckler so far and really enjoying him. I think I'd like to reincarnate him starting off with a level of rogue. The utility of opening locks and disarming traps would be nice. The sneak attack would also be a bonus, being a halfling. I already have a lot of bluff, and a lot of gear benefiting open lock, disarm device, sneak attacks, etc.
My only concern is that it might lower my abilities at being a bard. My healing, buffs, crowd control etc would be weaker? I'm not sure how much a level or two of rogue would change him.
I am using the build The Count of Monte Cristo but slightly modified for my personal tastes.