1.) I have had both good luck and bad luck hiring people in this chosen profession. If you have hired, or tried to hire, anyone to do repair work or construction projects, I'm sure you have your own stories, both good and bad. I'll leave it at that.
2.) Only a chosen few understand business etiquette including, but not limited to, returning calls, showing up when they are scheduled. And apologizing when they stand you up.
3.) Warranties, from many that we have hired, are simply sales tools and mean ABSOLUTELY nothing. Don't spend extra money for them. If they offer it as part of their service, of course you need to take it. Hopefully, they will honor it. Cross your fingers.