Dominatio:
There are no stupid questions, only stupid answers. Please don't be put off asking any questions.
There are VFR rules and IFR rules but you can also have your own rules (as long as they are in addition to and not subtracting from the 'official' rules). Personally I would find it slightly mad to fly above a fog bank in a SEP whether it was legal or not. Always always always consider whether you have an out if the fan stops.
There are airfields that my clubmates have no compunction about flying to that I avoid like the plague because the approach/departure is over housing/industrial estates etc. Likewise I have an IMC rating or whatever it's called these days but I won't take off unless the cloudbase is 1K or above even though legally I can do so. I don't want the quiet bits to start when I'm at 600' in cloud.
There's the legal part of flying and then the common sense bit.