Hi @Arta Montero! As the other poster's have said, it may be time to cut ties with your PM. In no way, shape, or form, would I feel comfortable or honest with myself if I sent over a maintenance tech to unplug a shower tub drain and charged one of my client's $500 to do so.
As @Joseph Firmin said, those don't sound like maintenance issues - stoves get dirty after being used, tubs not draining after a female using them, and preference for length of blinds are all not "maintenance" issues. They are all things that the tenant has been responsible for causing. At the very least if the tenant was going to complain about those types of things, the tenant should have been responsible for the cost of "maintenance" calls since they are not in fact maintenance issues like a broken water pipe or dishwasher.
This sounds like a huge mess and I'm sorry your PM has put you in it.
First things first: I would speak with your PM and discuss with them how displeased you are with them. Then I would clarify with them what maintenance issues are tenant related and should be charged to the tenant or for the PM to troubleshoot with them over the phone to fix the issue.
Depending on how that conversation goes, you will know what you need to do with either keeping or firing them. If it's $1,000 to get out of the contract with them vs. spending thousands more on BS maintenance issues, I think you know what do to.
In my market, DFW, Dallas, Fort Worth, & North Texas - my company strives in situations like these, which is why I like how stringent our tenant application process is - we get great tenants in for our clients. We do month to month agreements with property owners and we do our best to minimize their out of pocket costs... why? Because we want them to buy more properties and increase their success and they're happy with us so we get to manage their next consecutive properties! Just like you were/are doing with wanting to buy more, we want the same for our clients.
I hope this helped!