First part..........nopes........go to a pro detailer.....or even an amateur one........clay kit you can do yourself...no worries on it, compounding part, yes doe need a little skill.....an then polishing...needs to be inch perfect for that cool n smooth finish.....how old is the car yer working on ? Does it really need a compound ?
An yes the sastay mf are the lesser evil.....but on par with branded mfs.....nopes......
visible difference in the finish depends on the app, base prep an tons of other factors, personally I`m Megs fan than a mothers one