I quit this game a year and a half ago for League of Legends. Not because I like MOBA games more, but because this game was in such a pitiful state, and it has only worsened.
First and most importantly, the lag issue has to be dealt with. Soldier Front is the only game I've ever played which gives people with high ping an advantage. To be killed behind walls, by grenades that you didn't even see, or by people who walk through half the terrain is absolutely despicable, and is my biggest peeve out of everything in Soldier Front. Get that fixed and I honestly will make a great attempt to come back to this game.
Second of course is hacking. While it's a problem for a great majority of games, and compared to Combat Arms (which is on such a lower tier than this game), we have it good. However, the problem still remains and all new advancements to prevent hacking is widely and graciously appreciated. This Kita person is obviously deranged to ruin the fun of probably 100's of players by now, but the fact that she is able to do it marks how horrid a company Ijji was. Aeria will earn great reputation throughout the serious SF Gaming Community if she is dealt with swiftly and with as much closure as possible.
Fixing the other bugs, like the most irritable reporting problem would be delightful, too.
As for attracting new players, I'm not in advertising so I can't really help you. People love free stuff, but I suggest, like back in the days where the Dragon M4 was initially released, a set amount of time, or kills, or games should be required to receive these prizes.