Nothing you mention is "ordinary" and you should charge for all of it. dodged a bullet there thats a very good price take it from the security deposit and call yourself lucky. 

Do you have a 501c3 that you operate under (and rent the house from yourself), or do you purchase homes with an LLC or personal name, and run as a regular business? 

So, your focus may need to pivot from high rental cash flow to little to no cash flow as a rental with an appreciation upside.I would recommend taking your $150K to $200K and securing a solid equity position in something that will cover its expenses and maybe provide a small cash flow, but then is poised to appreciate nicely over the course of the next several years. 

My goal is to create financial security for retirement.

Your best/safest bet would be a regular lease combined with an option to purchase.

This is primarily what makes their work product substantially lacking in correct English grammar, legal protections, timely professionalism and many other ways any Securities Attorney will point out to investors.

Depending on your debt to income, you might have to sell or have an executed lease to secure financing to buy the second home.

By all means give them a note on how to use all of the appliances (eg clean out the lint trap on the drier after each load, do not use dish soap in a dishwasher, change the furnace filter regularly, etc).

Possible (but I doubt easy) if seller takes a 2nd / subordinate position to the bank or is secured by other property you own.

Using a HELOC or home equity loan on your personal home could be a good option, especially if you can secure a low interest rate and manageable terms.