The colors are right; as I said, I had to send the BombDrop message if the player is on T, and HostagePos if the player is on CT.
As for the Radar message...you have to send a userid along with it, and only id's on the same team as the admin are shown. If I were to use the Radar message to show an enemy, then I'd have to take away the blip of a valid living friendly in order to see them (the enemy).
I wish there were another way, but from what I've heard, there isn't...
http://forums.alliedmods.net/showthread.php?t=458
As for only admins getting the messages..the more people that the plugin has to send the message to, the more it bogs down the server. If you really want everyone to be able to use it, though, just set ACCESS_LEVEL to ADMIN_USER.
Finally, the cheating...ya, it could be used to cheat. There are a lot of plugins that could be used to cheat; that doesn't mean that they SHOULD be used to cheat, though.
http://forums.alliedmods.net/showthread.php?t=8167
I'm sorry to everyone if anyone decides to use any of my plugins to cheat, but please don't take it out on me; I'm just the messenger. :-\