We currently have two "playgrounds": team deathmatch/siege (newcomers paradise, but overall a big chaotic "bash their heads in"-playmode) and skirmish (tactical gamemode for veteran teams). The problem is that there's not a real place to go for people in between, who want more challenge than newcomers, but don't have a elite group to play with for skirmish
A variation of team deathmatch would be nice, something thats similar to the warband team deathmatch, with short rounds, no respawn, friendly fire activated, call it "classic tdm" if you will. A gamemode like this would fill this huge gap, since it rewards an advanced playstyle, yet doesn't require that much teamwork.
The only issue is that, once there is friendly fire, griefers will be there aswell, so a kick poll system might have to be considered
Siege could use a "friendly fire" mode aswell, there's just more tension when you cant blindy swing/shoot at enemies without the risk of hitting your teammates
oh and please add a duel server, lately me and my buddies surprisingly met an old rivaled clan in skirmish and we all simply turned the game into a big duel server. After playing that, I want a duel server even more now