First of all, all weapons should at least be roughly equally useful or viable, instead of the current meta that essentially discards any weapon that fires slower than 800RPM
I'd personally love to see more burst-fire weaponry like AN94 or classic FAMAS F1, perhaps AUG available in multiple categories (LMG, AR and SMG).
What about realism in weapons? Will many support the realism of mods to weapons? That is, if the modification is suitable for the AP system, then it does not fit into the AK system, or a modification in real life is not installed on the weapon, and in the game it should not.