In relation to running the LLC, keeping a book of business, maintaining the LLC in accord with the compliance that the Secretary of State requires (if applicable), and having an annual meeting are things that you should consider doing. 

Since my husband had such bad credit, I only have myself on the application.

Im still waiting on the rental application, but most likely they wont be leaving the house much.

A title agent's role can be considerably different than that of say an auto insurance agent or life insurance agent who basically takes the application and submits it to the underwriter. 

Just pick the best applicant so they don't ruin your house.

Should the current tenant have the "possible buyer" do an application prior to selling it to them to make sure I accept them?

Even for very nice homes that are in high demand, we have received few applications.

You or your contractor will be required to personally meet/call/otherwise communicate with the inspectors at be for whatever building code subdivision you are working with, to see why your applications are being rejected, what it is that they are actually looking for (and then if that is actually legally permissible to be required or not!)

I am using Cozy as my rental application platform, but I think it’s an obstacle for my potential tenants.

They may require a down payment from you.. may request a formal credit application from you requiring that you qualify based on your credit.. lender may or may not release your seller from the note which then may affect your DTI based on exactly how it is structured.