I talked to them earlier this week and was wondering the same thing. 

I am staying wondering why there is so little information on tax liens,  i read some books on notes and foreclosures but looks like a big secret here... maybe that's the reason... i need to go into this to find out :)

I inherited a property management company but just wondering what others are paying for similar services. 

I am wondering if you are making some assumptions that just aren't true. 

Overall, I've lost confidence that he is doing a good job and wonder what else he has missed if I was able to catch the mistakes. 

This is one of the things that @Matthew Irish-Jones mentioned above - be careful about putting #3 on his list above #1 and #2.

Owner shouldn't care about your DTI.

The previous owner took exceedingly good care of the building and there was nothing that need to be done except to raise the rents.

I kinda get it if 4 and 5 bedroom properties are going for 1.5 million in that market but... thats just math wondering what reality is?

If something breaks they are going to get it fixed - but you want to be careful about who they call.