The list below may include suggestions which other players had already mentioned, but I want to summalize all what this game needs now in my arrogant opinion.
- Muskets should be a bit more inaccurate.
- Rifles should be a bit more accurate, but much more slow in reloading.
- There should be accuracy&reloading-speed penalties while moving.
- Bunny-hopping must be disabled! Bunny-hopping for dodging bullets doesn't look like a gentleman.
- Surgeons should receive some score points for healing friendlies.
- Cavaly is desperately needed in the battlefied! Because cavaly's presence limits skirmisher's effectiveness and in the same time, raises the importance of "formations" in the field.
- Kick&Ban system for hackers and spammers is needed.
I haven't spent much time in naval battles, so I can't suggest anything but a spawn bug for naval battles.