I would send a service man out there , to look at the system , and then tell the tenant they have to order a part , you will let them know when the part arrives , but we will be over to collect the past due rent today .

If it is a COA, F.S. 718.116(8)(c) provides:(c) An association waives the right to collect any moneys owed in excess of the amounts specified in the estoppel certificate from any person who in good faith relies upon the estoppel certificate and from the person’s successors and assigns.If it's an HOA, F.S. 720.30851(3) provides:(3) An association waives the right to collect any moneys owed in excess of the amounts specified in the estoppel certificate from any person who in good faith relies upon the estoppel certificate and from the person’s successors and assigns.Now there are Master Associations that have an HOA, and the MA has condos built inside them with a separate COA, so some condos can have two assessments, one for the HOA and one for the COA. 

A promissory note and deed of trust are important but there are also other disclosures and documents you should collect to help protect the loan - Lender's Title Policy in 2nd position behind the bank loan, Loss Payee on the hazard insurance policy binder behind the mortgage lender so your parents get reassurance they'd be paid back if there were any claims that need to be made.

Very excited to continue to dive into this line of asset collection and hopefully build a great portfolio for myself!

Also there are plenty of rent scammers out there saying they have a rental and collecting app fees on a ghost house and sometimes even getting a deposit.

My place sleeps a lot, and so, is often rented by large groups of "friends", no one with a majority stake in the collective negative outcomes of their behavior. 

It is increasingly common for a PM to charge a "leasing fee" which covers all the costs of marketing, showing, screening, placing tenant under contract, collecting deposit and rent, setting up utilities, getting the tenant placed, etc.If the PM can't justify the cost, then they shouldn't be charging it.

Can I still make an LLC and just collect the rent and put the maintenance and mortgage payments through that LLC?

As a property manager I had every incentive to collect before paying out the owners.  

This way, maintenance, repairs, and taxes are the responsibility of the new owner, while you continue to collect principal and interest, potentially as tax-free income.I'm not a CPA, just a heads-up 😄, but you could possibly avoid capital gains tax with this approach.