I asked that they pay the late fees and turn the security cameras back on. 

-Identify their specific needs, such as cash flow, tax savings, wealth preservation, or growth, to tailor your approach.

the company is paying the bills so even if the doctor has bad credit it doesn't really matter about getting the rent check... 

You will get what you pay for, so I'd recommend gaining clarity on what you want out of your CRM.....

There is a cheaper program with access to the course modules, online platform but you have to pay $200 an hour to talk to a coach.

Just saying.. not sure about rentals though all of SC is a little tougher given the property tax situation for non owner occ.

what if one starts tormenting the other but always pays rent?

Personally, I wouldn't totally disagree, but it is very much in the eyes of the beholder what "nice place to live" means.Based on your post, I would assume you are getting requests because you are a new landlord (maybe the old one was not a kind person, so tenants chose not to make any requests) and that you are asking them to pay more rent for a unit that is likely in worse condition than when they moved in.So now, you can either tell them no, or you can accommodate and potentially open up pandoras box of setting expectations that you will cater to all requests all the time, or as noted, you can remove yourself from the equation and hire a PM to handle the requests.  

When a tenant pays rent, I apply it to the oldest month of rent owed first.

The tenants must have a strong application and a landlord reference with the cat, pay a larger deposit and higher rent, and they are inspected more often.Nothing will stop the odor.