Sorry to intervene, but "expoits" and "security risks" aren't limited to DCC send/get. To put it different: stating you're safe as DCC had been disabled is plain wrong.
Malicious scripts are able to do virtually as much "bad things" as any other malicious piece of software could do: manipulate/corrupt/delete local files, collect sensitive data, send/get files/data without your knowledge, what have you.
This doesn't mean most mIRC scripts are potentially dangerous or even written with bad faith. It simply means scripts can be powerful tools - for a lot of uses and, sadly, abuses.
You should treat unknown scripts the way you would treat a unknown application: don't load them if you cannot verify they derive from a trustworthy source. Also don't load what you don't need. You wouldn't doubleclick that "unknown.exe" either, would you?
The same goes for unknown commands: don't type something just because someone told you to.
That said, You can never have 100% safety. Though if you follow the above and generally known safety measures (up-to-date antivirus software etc pp), you don't have to fear mIRC more than, say, your web browser.
because they are using this chat IRC software to make a connection with the target's computer. I am no expert and I don't know much about IRC but it seems logical that if IRC prevents them from sending/receiving files, then they won't be able to reach to my PC (because their request for connecting is ignored), even if script has some suspicious codes. but I might be wrong if a script can be that powerful to ignore IRC configuration options or even worse, lets some unknown individual changes the configuration ... 
