1.sort out bots, they freeze a lot at the start of the game.
2.snipers - when zoomed in, you are able to move your cursor to which ever side of the screen and the screen moves in that direction ... im not great at describing things so if you didnt understand that, click on this link (or paste into address bar) -- http://www.stickpage.com/stickstrikeplay.shtml -- (same controls as cs2d(press 5 when you have found the sniper)), and press play, then get in a game, get a sniper and see how, with the sniper, you can move around the map with your cursor without actually moving your terrorist/counter-terrorist. With fog of war, it would be the same thing as above, only you wouldn't be able to see any player action (but still see the greyed out map) if you were looking through a wall.
3.killstreaks - there should be an option in options to turn killstreaks on/off. it would make the game more interesting - see call of duty 6 (or 7) for ideas. you could have a killstreak selection page. things like harriers or helicopters could be 0.5 seethrough (0.5 referring to one of the options when you click on a sprite in editor) and seeable in a certain radius in which the player called it in. It could also add to that players kills and maybe count towards his/her next streak. In the game mode zombies however, killstreaks would automatically be turned off when a server with game mode 'zombies!' started.
4.Capture the flag - i don't know if i speak on behalf of others, but it gets a bit annoying when the whole round starts again everytime the flag is captured. again im suggesting an option turning a time limit or score limit on/off. For example, say the 'score limit' was on 3, A team would have to capture the flag 3 times in order for the round to restart, change map etc. Or with time limit on, say, 5 minutes, the team with the most flag captures at the end of that 5 minutes, wins. and also, if the (for example) CT flag carrier died, a T could then pick up his own flag, and go and hide or try and defend the red flag that would be on his back. Of course he would apear as a red dot on the radar, and probably soon be found. However, if the T didn't want the T flag anymore, he could either run to the place where the T flag is ment to be and return it instantly, or he could hold down a Key on the keyboard, for example, if he held down the 'k' (default key for returning flag thats on your back, in this example), a yellow bar would appear (as it does when your reloading or planting a bomb etc.) and it would take him 10-15 seconds of holding down 'k' to return the flag from where he stands, however if he is hit by an enemy shot while holding down 'k', the timer would then restart.
5.radar - I think (and i know i speak on behalf of a lot of players now) that the radar should be like the one in counterstrike source. For a map the player has made, it would be a simple thing showing the walls and obstacles, a bit like the mini-map in spectate mode, only the map (when playing) would only reach a certain radius - so basically exactly like the one in counter-strike source. For more advanced things, a red dot could appear on your radar when an enemy shoots their gun. A gun with a silencer would not appear on radar. And also maybe the helicopter or harrier as i described earlier could appear on radar.
PS. sorry for the length of it but at least the ideas are described in detail
Will
and i forgot, I think someone has already said this - but a tigger_random that as the person said earlier, could trigger a random door or a random item. It could be a switch or something you hit or something you move acroos.