If you didn't get your own inspection and make the inspection repairs during the rehab, the buyer's inspector could find a hefty list of inspection repairs that need to be fixed and repaired.  

(Two tenants, bounced checks twice - ugh) I use the method of each tenant gets an invoice created each month, then I accept the payments, create a deposit and record it, and take it to the bank.After a few days the deposit shows up in QB and it gets matched to my deposit in QB.But I just have no clue how to account for these bounced checks since the bank has already matched them up with QB. 

My second option is fix and flip out current home we bought last year.

That will not be a cheap fix. 

If your current loan was originally for $340K and you are still paying $214/mo. in PMI, I'm assuming your monthly principal payment plus the PMI is @ $1,808/mo. on a 30 year fixed.

The appraisal came back and the lender is asking for things to be fixed before they can make the loan. 

His only concern is that the turnover is a little bit higher, but that may just be the area and not the type of property.His deal is still profitable because he's doing a lot of the fixes himself and the units are pretty nice.  

So a house could have been standing vacant for MANY years before it ever goes to the sale and just might be so bad that it's not economically feasible to fix it. 

I was able to fix most of the plumbing yesterday. 

To me what will really determine whether you overdid it or not is if you're able to get the rent that matches the quality of work you did.