Yes, all the stock screws on the carb are easily stripped. Unfortunately, the carb drain screw is the only one that cannot be replaced with a socket head screw.
Try the screw extractor.
I put a bit of anti-seize on the threads of the drain screw to make it easier to remove.
Yes, but it's not that hard to remove the bowl, 4 screws... that are also easily stripped. Replace them with steel socket head screws... then be careful not to over tighten them or you may strip the aluminum threads on the carb.