Dude you really need to learn how to fire customers. Honestly was a hard lesson for me too as you never want to turn down a paying job but it's worth it. If we see multiple issues during a service call, my quote is for repair of those multiple issues. We all know if we repair one thing it likely won't fix the issues and now we got a callback. I'd rather price myself out of the job than have to deal with multiple callbacks and the headaches associated. We tell everyone this up front, we're not the cheapest but we're thorough and professional. Once you realize the good customers take up a fraction of your time (normally) and leave you in a better mood you honestly produce more and have better customer interactions.
On reviews, man first off I think we all overestimate when someone says "I'll tell everyone" how many people actually listen to these miserable fucks, and two how many people they'll actually tell. Google reviews, you're never going to be 100% if you have a lot just the nature of the game. Honestly we get 1 star reviews about driving and I check my GPS and it was another companys truck. Biggest thing is make the happy customers the advocates. Offer a discount, gift card, something for leaving a review on the business. It's a numbers game, it's impossible to make 100% of people happy about spending their money, but for everyone person mad and ranting you at least want the happy ones doing the same.