Okay, I'm getting there.
It's working now, sending and receiving, and I'm sort of getting what I want (only after looking very closely at the chat-demo though, maybe I'm just... stupid -.-)
The problem that I'm having most of the time that all liteC tells me is "crash in...", which is not being very helpful.

"ATTENTION: In the client/server mode the event is called twice! Once for the server and once for the client! "
there's no workaround for this...?
I mean, the host doesn't know whether this event has already been received by him or not...
I just get all chat messages twice on the host...
and I can't figure out how the chat-demo does it...

Sorry, again, piling up the questions. I just wanna get these basics down, thanks to you I've gotten MUCH further.

[edit] oh, and a feature request: could you make enet_get_playername accept empty strings somehow? I had quite a few crashes because I did this at first:
STRING* tmpPlayerName = str_create("");
enet_get_playername(senderorsomeone,tmpPlayerName);

this:
works fine though.
Since the program just quits it was very hard to find that bug.
[edit]