1 I'm and engineer, problem soln is just a natural process
2 I have MS and haven't had normal feeling in my fingers for almost 23 years... so I do threads as little as possible
3 it is never coming apart, is it? if not why use screws
Do yourself a favor and buy an air riveter, even the Harbor Freight one will improve your attitude during a big project (unless you want to build up Popeye forearms!)