Hi there,
what do you think is the best class for cadence gunslinger?
I think about shaman because of aoe (grasping vines) and bleeding debuff
through locust swarm.
Maybe occultist is viable too because of COF with rend…
What do you think?
Commando is nice but iam really worried because the lack of aoe.
Cadence+falcon swoop is not enough 
Commando is probably best for that tasty total speed bonus on Vindictive Flame and the flashbang debuffs. Bleed is more of a tertiary damage type on cadence so I wouldn’t build around it personally, but I’m sure it would still work decently.
For the record, falcon swoop AoE with piercing cadence shots is definitely enough AoE to get through everything assuming that you have enough attack speed to proc cadence’s pierce shot often.
Commando is fine for this build, as is Witchblade…really up to you. Damage is about the same, but I prefer Commando as I’m more used to the survivability of Demo.
It hasn’t been updated in a while, mainly because not much has changed to make a significant difference, but I did a build thread way back in 1.0.0.6: http://www.grimdawn.com/forums/showthread.php?t=48690