Watermarking your photos may be a good way to prevent scammers from taking and using them.

Which assets in a home do you always make sure to follow the manufacturers recommended preventative maintenance schedule?

You'll end up paying $127+4k for a house that the market has demonstrated is only worth $130k and you will have done so with someone against you, not in your corner, rooting for their $4k fee regardless of the fact you're making an investment that the market testifies is backwards. 

It prevents me from stagnating.

Long story short, I have more than 10 mortgages including a primary and it's preventing lenders from working with us to refinance, cash-out refinance or even take out more loans. 

This is because electric bills aren't very high, and you pretty much need to run the AC 24/7 to prevent mold.

I would also limit my interaction and communicate only in writing to prevent them from getting into an argument or wasting your time.

I need to mitigate the damage that may be incurred if they do, or simply prevent them from accessing it. 

While this can serve to filter out some non-serious applicants, it can also prevent some well-qualified tenants from applying when there are free applications for similar units in the same market.

For example, my lease says (in part): "Tenant shall be charged for repair of drain blockages or stoppages, unless caused by defective plumbing parts or tree roots invading sewer lines."