Re: PA system success
FP is right about the headphones, no real point trying in your situation, nothing like a little walk and putting your ears where it matters, the air between the speakers and the audience will sound so much different from headphones.
I hope by sock over the mic you do mean windsock.
As for lugging the gear around, often people don't see the value in paying for production until they do it themselves and have a technical shocker, or experience the full sound guy experience, labour and all.
Glad your shows went well.
Hereby & forthwith, any instrument with an odd number of strings shall be considered broken. With regard to mix levels, usually the best approach is treating the mandolin the same as a cowbell.