There is a legal concept that when a contract is ambiguous that it will be interpreted in favor of the party that did NOT write the document.

Call previous landlords...was there police calls, missed rent payments, parties, complaints, etc. 

I then had to resync it all over again.Even QBO has sync issues but at the very least they make it very obvious that it isn't syncing lolI think the issues is more of a 3rd party that they use like Plaid and others

Without knowing the appreciation in the area you bought, that part is hard to answer, but just given your numbers I would definitely sell.

Obviously would change from person to person, but I'm curious what people have used before that has been effective for both parties. 

Then there are other items that are negotiable in terms of marketing to get the place rented or at time of signing lease between the two parties.

That said, in Florida, the parties can enter into an agreement that qualifies the tenant's and landlord's use of the premises.

For my part, I wouldn't call anyone who started out with "don't waste my time."

Another may see it from the perspective that they've been getting a free ride all this time and now the party has ended.

You can ALWAYS negotiate if both parties want to and with you having the option to back out of the deal you have the ability to leverage the seller into "wanting" to negotiate.