All working fine here.

Nope no issues like that. No crashes at all now.

I get a launcher crash after about 20 minutes or so, seems to be happening everytime following the last Steam patch; I had them at first then after a couple of beta patches they seemed pretty rare, but now this launcher crash is occuring fairly regular, just when a mission's getting interesting:(

No problems here.
You guys with Launcher crash, probably only have 4Gb, and I have seen my dwm.exe use above 1.2Gb after running CloD , usually stays 60-70Mb.
dwm.exe is desktop windows manager.