Since that time it's tremendously appreciated in its value and now I am thinking if I should sell it or continue renting it out perhaps for another year or so.

Continue with the education, but I would also say to look into local investor meetings.. the members will likely be happy to help you with some documents they have used locally in deals and a bit of guidance.

I would also continue to search and compare software on Google to see what your best option is before settling on QuickBooks.

I've been able to continue making purchases only through private, off-market deals.  

At that point, you can decide to work together or that it might not benefit either of you to continue.

Or you find out that your PM found his wife under the keyboard player of an 80s cover band last week and is locked up for ag-assault in the county jail for thirty days with no one available to collect rent or continue the process of evicting those people on Center St. who might or might not be running a under-the-table daycare center/illegal pain pill distribution center out of your property...Does your whole house of debt collapse because Murphy wasn't in a good mood this week?

Do I continue with the deal knowing that the cash flow is lower than expected but just get into action or wait until another deal and continue waiting knowing it's a sellers market? 

I never heard before of the matter until Friday, when I asked him to get back to me with a buy out offered as he had said 2 weeks prior or I would had to get legal counsel.The question here is: Should I take his buy out offer or continue waiting, when I don't trust him anymore?

I'd rather not ask my agent to continuously make offers with a 1 in 20 success ratio (or lower). 

So continue to network here and build the rapport, and get to know others who are doing what you want to do.