First suggestions would be the addition of more shotguns.
The current selection has very few potions, of which only one is allowed attachments (SASG-12)
We could use some more shotguns, smaller ones, with attachments.
We have a lot of options for SMG's, Assault Rifles, snipers, and even LMG's. The only thing lacking are shotguns.
A few nice shotguns:
DP-12 Double Barrel Pump 12ga
Mossberg Maverick Thunder Ranch HS12 Over/Under Shotgun 12 Gauge
UTAS UTS-15 Pump-Action Shotgun 12 Gauge 18.5" Barrel 15
Fabarm Shotgun
Probably some more, but lets keep it at these for an example.
While the Saiga 12 works decently, its quite a large gun, often overshadowing assault rifles, or even some LMG's.
Some people might like it, but for those who like a shotgun as a secondary options it might be a dealbreaker.
Or people who love the compact look, with some stopping power. You have the Super shorty for that, or a collapsed SPAS-12, but the first only has 2 shots, while the second has the worst sight picture in the game while in compact mode (personal opinion).
Some might say shotguns are useless, compared to an AR or SMG, and depending on the usage/ situation i can agree.
But be it RP or Playstyle, some people like the more "personal" approach of a shotgun.
For me personally it's both RP an Playstyle.
I just love shotguns. They work simple yet are effective (and often look nice).
Always going with headshots or spray-and-pray takes the fun out of it pretty fast for me, but thats me.