There are several types 'zombies' (for lack of better term). The sapper (armless guy...perhaps two variants), cloak, a UAV that will fly overhead and if you hear a modem sound will spawn AI that will hunt you.
The skinny sapper will always try to come up behind you. If he gets close enough he will explode. The fat sapper I've not dealt with much, as he's new. He has a really big explosion. If you kill one of them, most of the time they will emit a green gas. Do not go near it, it is toxic (as are snakes). After the smoke dissipates, you can search the body.
Also, if you kill any of the AI currently on the server, look around for krypto near them. It'll look like a cell phone. Its money, take it and put it in the bank (more on that later). When you're looking at it you'll see "Take Krypto." Sometimes its a really small area you have to zero in on.
Still lots of AI. I don't know where they are coming from. I thought I took most of them out. I'll have to see.
Something with one of the mods is fubar'ing the server. I'll narrow it down a bit tomorrow hopefully. Bman has some really neat buildings and map additions that are really nice. I'd like to at least get that up.
RE: where you are on the map. You can't see exactly, but if you'll press the little circle up top on the right of the map screen title bar, it will center the map on your location. Not really useful, but will give you a vague idea. Finding a GPS unit will give you your co-ordinates. You can (semi) triangulate positions on the map as well. I think its shift-mouse click to put a way point on the map. Do that a couple of times and you can get an idea of where you are as well. Or at least how far it is to get to where you want to go.