its a good and interesting concept, some of the things you're suggesting are "a bit much" for most spriters
there are servers with certain themes and focuses on certain classes hence why the gunslinger on the server u mentioned would have had a motorcycle mount.
however our server has no such focus, we're balanced to as much an extent we can on these higher rate type servers.
im pretty sure at least that portion of the suggestion will be rejected, because while we have customs, this server typically sticks to the skills and limitations of most classes (Most, because as of late we have a 1-handed sniper bow)
the idea for the revamping of the gunslinger class as a concept is good. i'll add in the fact that while giving gunslingers a shield may become overpowered, they should find some way to tank single normal asuras for the least somehow (give the gun calculated demi or neutral resists or something)
full asuras should at least by right take them out. and considering a champ going full asura is gimping out on life, i find that it would be more fair for such and ordeal.
gunslingers do enough damage, and if you play right, as most do they can be very lethal.
btw love the specifications on the e.weapons your suggesting xD
if i may, i wanna put in my bid for an m4 Ar with a no0b tube. except allow it to make my aspd 199 and the n00b tubes cast meteor storm by a 30% chance LOL JK! (sry i had a bit of fun with that one)
overall good idea, and welcome to the server
oh and gunslingers look cool for the most except for the open chest area thing going on. i guess some sprites could be made to give them proper clothing or something, its as if they were ymca or something now lol
edit:
oh and as for the turret thing, Gunslingers do have other skills beside desperado
if the "turret"- type weapon would be iplimented it could do something similar in effect to the Lord Knight's halberd and improve damage on full buster, gatling fever Or tracking or something (BTw my N00b tube thing =Ground drift so ya it legit idea menz ./gg)