Ashley, so far so good and I'm a bit skeptical as well... What about the editor's treatment of web fonts when compiling a preview? Is it possible that a glitch during compilation could cause a crash shortly thereafter? The mini default font during preview was odd and always indicated that the editor had crashed, as if the editor/compilation process found the font incompatible somehow.
Also, it is like running a different prog now. C2 is blisteringly fast, and - regarding whether something else caused the fix - I was careful to make incremental changes and test until the next failure to avoid the confusion that would be caused by making multiple adjustments at a time. Never say never, right? But this looks like it has sorted it...
I have one extra plugin remaining (CB Hash, can't write that one myself in events) and I will certainly report a bug somehow if this recurs.