The tenant proudly told the repair man about his knowledge of hvac systems, and that he had made the modifications to try and fix it, but that it seemed to make things worse.I told tenant that they would be responsible for the repair ($1300) since they damaged the system, and the tenant agreed. 

The relationship between the client and property manager is vital to an owner meeting their investment goals.  

He’s been vital to my past investment properties and I’m fiercely loyal to him now.

Look at it this way, they sell the module software for $10k-$20k per package, 2 week modification.

Unfortunately, I rarely say everything I want to say and cut my conversations very short or leave out vital pieces of information which only confuse my audience even more.I'll be following this thread for the same advice!

It's part of the modification agreement.

There are some that view the importance of the institution of marriage not in a religious way, but as being a vital part of the glue that holds society together.

Fellow Maryland investor here.You should not require a permit for anything you've mentioned.If you're not making any structural changes nor making any major electrical or plumbing modifications, your job is more along the lines of "upgrading" (no permit) rather than "renovating" (permit needed).You could always call the county's permitting department.

I agree with @Bob Ebaugh and @Tammy Vitale - $1k over asking is not that much, depending on how the property was priced.

When you do the title search, some properties will have lots of recordings - things like deed transfers back and forth, multiple mortgages in place at the same time, subordinations, mortgage modifications - all of these sorts of things add complexity.