they have had a lot of deals lately. but if you notice, their estimated returns are lower on the newer deals, so it's not like they are assuming that things will still remain as hot as they have been in the past few years. the newest deal also has 2 different classes of investors, one for cash flow only and another that shares in the gains. is this approach better than the others that are slowing down their deal flow?

You + wife get your initial $20k back, partner gets $88k, and the remaining $42k is then split between outside partner and you but you get a large portion of it (for example 60%). 

It's not uncommon to find several mortgages and satisfactions recorded (because every time a refinance is done, the previous mortgage is satisfied (hopefully, if everything was done right) and a new one gets recorded.

Hiring a GC, and payout when complete, every step of the way, is how you should do your next flip.Bottom line, is that you now know what happens without permits being closed, and a punch list being satisfied before payment.You are smarter now.When the bruises heal, your next flip will go better!

The fact remains that you accepted an offer. 

Our housing prices have remained slow and steady over the years and we get great cash flow.

To remain "cool" a heat exchanger requires a constant volume of airflow.

If you do nothing with the remaining $65K and once you pay off the $35K you borrowed, then you're back up to $100K in "available funds" and you can start the cycle again.

Am I allow to add a late fee payment on top of the remaining balance since they did not pay in full and the grace period is over for late rent?

I have the Pro package and am really satisfied.