Withhold the amount from their security deposit if allowed.6.

Your enforcement remedies under law are: 1) deliver a notice to pay per F.S. 83.56(3), 2) make a claim on the security deposit when they vacate per F.S. 83.49, and 3) seek collection of unpaid rent through lawsuit or collection company. 

My partner are thinking to buy it first and THEN bring in the developer, but securing it ourselves first...Just trying to figure out the best logistics of all this...

Brining someone in for that 10% gap is likely better as a partnership or equity split as there's not a lot of security in lending on a 100% leveraged fixer. 

The lease agreement clearly states that the "Security Deposit", and not "Damage Deposit", does not have to be returned to the tenant if all the terms of the agreement are not met.

While there are returns and security in substantial positive cashflow, you also get returns through appreciation, tax deductions, and loan paydown.

I’m a wholesaler and was told to NEVER leave a potential buyer and seller alone together during a walk-through because the buyer could go around me and try to steal the deal.QUESTIONS:If I’m under contract with the seller and it’s filed with the title company, how could a buyer do that without it being breach of contract by the seller?

It's always better to go off a referral with a proven track record rather than a random number from a Google search.One caveat to consider is that without owning prior real estate or a primary residence, securing long-term financing might be more challenging.

His name is on the construction loan and it is secured as well as the cash to purchase the property came from a heloc from his personal residence. 

So, talk to all the people you know about what you want to do.And hire a good securities attorney.