Among the biggest complaints people have regarding composting is it smells. For those who have neighbors nearby, you might want to think about that as well! If there’s an asshole gene, that means assholes may be eradicated. They’re nothing but a lot of Hippocrates.
Perhaps you would, but that’s your choice. To be able to function properly, the tumbler must be filled all at one time, so isn’t suitable for adding material only a little at one time. Just add new material in addition to the heap. Not my favored alternative, but will surely work.