I have an SM58 microphone and recently got a stand for it. Is it bad to leave the microphone in the clip - will the clip get worn? Thank you!
Among the many cases I had to deal with something mic-related failing (most often cables or stands, but also microphones themselves, including the sturdy SM58), I can't recall ever having problems with a worn out mic clip. Some mic clips are rubbish and have been right from the start; these would likely have failed if I'd used them for longer, but a good clip (even those are pretty cheap) should live a very long time, no matter if you keep the mic in or often switch.
Regardless, I recommend properly stuffing away all unused mics for the reason that compacted stands and neatly rolled cables tend to make for less net work (and in particular less nasty surprises when under time pressure) than the cable salad and obstacle parcours that “I'm gonna use this soon anyway, I'll just pull it over here...” laziness leads to.
Treatb the microphone with a bit of care, the SM58 is a rugged old warhorse but you might as well keep it un-dented! I wouldn't worry about the clip. They rarely break unless they get stepped on.
The clip isn't likely to get worn out very fast. Furthermore, the clip will actually likely get worn out faster by having the mic taken in and out than by just staying in the same place all the time (plastic fatigue).
Clips aren't at all expensive; a cheap one can easily go for 5 USD. I wouldn't worry about wearing it out unless you are really hard up on cash, but if you really want to be careful, personally I would opt for leaving it in the mic stand. (Unless, of course, there is a risk of the mic stand getting bumped or knocked over.)
Best place for an unused mic in a used room is in its case. The clip won't wear out, but the mic will get knocked over, and that's not good, even for an SM58. Get it out of harm's way. I've had to replace the mesh on so many SM58s, that people leave on stands that it hac become obvious that the best place to leave a mic - any mic - is anywhere but in its clip.