Alucard gunslinger

[Elgate]

Hello, I'm trying to create Alucard from hellsing, and I think I found the way to do it. I'd like help on how to evaluate DPR and what item I can use to improve this build. (it is purely for theory crafting, i'm trying to see what's possible going down that way).

Race Dhampir (bonus to dex and charisma)
Let's say 15 point buy:
7 Str 18 dex 10 con
10 int 12 wis 16 cha

trait: magical knack(bard)
1st level: Mysterious stranger(gunslinger):feat(precise shot)
Charisma to damage. Not that bad.

2nd level: Juggler(bard):abondant ammunation 3 times a day (thanks to magical knack and high charisma).
3rd level: trench fighter:feat(rapid reload), bonus feat(point blank shot)
4th level: TF:bonus feat(don't know)
5th level: TF:feat(two weapon fighting),dex to damage with pistols
Can't reaload without a free hand... yet.
6th level: juggler: considered as having a free hand even when holding 2 items and abondant ammunation 4 times a day.
7th level: whatever+1BAB class: improved two weapon fighting.

At that point, I don't know what to do and what to buy. I got (almost) unlimited ammo, 4 shots a round, dex and charisma to damage.
Maybe I should for something to heal me (i can't be healed with positive energy) but other than that, I really want to play something like that.