Typically a leasing commission for both sides is between 5-6% which would be split if there was a listing and also a procuring agent.Leasing space to tenants isn't always just about money.

In my experience, 15-20% markup on labor + materials is what you can expect from a "retail" GC, where the GC provides full-time on-site management, purchases/procures all materials, etc.

Even if you haven't paid off much of your mortgage, the rise in the value of your property since you bought it, could give you the equity you need to refinance or procure a line of credit.  

You must procure a flood elevation certificate, approx $600, from a reg land surveyor or engineer before I can quote.

If you find a great deal jump on it. regardless if its your home or rental property. if you buy a rental property first it shouldnt hurt your ability to procure a mortgage on your primary home as long as the investment property does cash flow. before you do anything speak with an experienced mortgage broker to set you straight.

If they did not procure a tenant and you did not sign a contract with that agent, there is no enforceable contract.

I have procured a triplex in Spokane, WA and am looking for Contractors/Consultants in the Spokane, WA area with 203k experience and bandwidth in March, 2021. 

The Lender is the client, since they are procuring the appraisals to use to decide on the loan risk.

Not exactly...the agreement names the specific buyer "or another buyer procured by the agent", which means only another buyer brought to you by the agent would be covered. 

First of all he has a contract, you can get it terminated, but if the listing agent ws the procurring cause of your deal, he is due a commission and he can hang you closing.