Just finished a scoundrel sawbones and I'm now leveling a gunslinger. I don't do pvp so I can't intelligently talk about that.
Gunslingers are more set up for ranged combat than the scoundrel is. I'm doing saboteur becasue I enjoy the aoe damage it provides. DPS is great. I do miss the scoundrel's stealth capability but didn't like the scattergun.
I suggest doing Biochem, Bioanalysis and Diplomacy. With these you can build medpacks, adrenals, implants & stims. As far as i can tell there is no medical skills with the gunslinger and I hate buying stims. The med stuff is also easy to sell on the market.
I'll be at the Lightspring soon and I'm looking forward to see if my gunslinger can get through it the first time without dying.