Adding an addendum after an original lease is signed (per OP) is optional for the tenant.

is create your entity and basic op agreement first with only 1-2 owners, then open your bank accounts and loans.

At this point OP is out of contract.

The OP was asking how this is fair or if it's legal/discrimination. 

The answer to OPs question varies by location.In tenant friendly CA the LL can charge fair charges for work that they perform and if it goes to court the LL needs to be able to show the charges are fair. 

I would stick to repairing the coin-op machine.

Since several responses suggest syndications, it may be helpful to the OP (and others) to provide some additional details on how to find good ones.   

Agents can certainly perform their own flips, manage their own flips and holds, etc.Regarding the OP questions, if you give up the acquisition commission for a stake of equity in the deal, you need to calculate how much of a commission you would have received and then calculate the money you should earn for project management, property management, etc.

Fred,Have you checked with your Co-op to see if they will allow and sign off on the HELOC or cash out refinance. 

Sounds like OP is looking to become his own PM and hire employees to work for him, but doesn't realize it.