My problem is that he says the security deposit is $1,420 which includes first 2 month's rent & holding fees which will be refunded if I don't like the place, which is fine.

Assuming he plans to flip the property after a 6 month rehab I anticipate he will make approx $50,000 - 75,000+ after selling/closing fees.  

We came to an agreement at $400k no fees, no repairs and the house was sold in 14 days.

Now they’re booking platforms, which is costing us a lot in payment processing fees.

The recommendation is to find a bank that won't charge you minimum account balance fees. 

IF they allowed you to 'roll it back out' if you wanted then it might be OK, but even then, I would think the fees in that program would far outweigh having an IRA, and you would have more flexibility too.A friend of mine rolled his into a SDIRA, and DOES do his new companies 401K with NEW contributions since they match those at up to 6% of his salary.

I thought HOA fee is supposed to be based on its square footage.  

Getting a license can be a good way to get started in the world of real estate, but make sure you are aware of the time (upwards of 70+ hours of real estate school) and the fees (usually 1k-2k) and startup costs.

I did have to pay an extension fee due to their closing date and the municipal search in that city, and the fact after we went under contract they allowed the basement to flood (finished space) and never told me until I found out myself the day prior to closing.

So before I start the attorney fee clock I wanted to get a better expectation of what I need.