When your a merely a intermediary, unlicensed, operating in a gray area, you lose your leverage. 

Private money brokers serve as vital intermediaries, connecting real estate investors with private lenders who are willing to finance projects that may not meet traditional lending criteria.

He/she can contribute cash into the closing and essentially act as the lender so that the 1031 Exchange ends up with all cash or the promissory note can be drafted so that the note is owned by the Qualified Intermediary and becomes part of the 1031 Exchange. 

The $10,000 would be taxable (i.e. taxable boot) in the year of sale since you pulled the cash out at the closing. 2) You can leave all of the funds inside of your 1031 Exchange transaction and have them all sent to your Qualified Intermediary for deposit inside your 1031 Exchange account. 

I have $400k at the intermediary.

So your Qualified Intermediary takes title to the new lot and when construction is complete transfers ownership to you to finish up the 1031 exchange. 

There is a specific process that has to be followed that includes going through an intermediary, etc., a certain legal structure that has to be followed in the investment, and all this generally involves additional time and expense as well.

Now, many intermediaries in the real estate field may argue that when they have a property under contract, but before they actually close, they may have equitable title, or at least an equitable interest in the property, and it is that equitable interest that they are selling, not the actual property (which they can't sell since they do not and never will own).  

You should reach out to a qualified intermediary and they'll give you all the answers.1.

And The qualified intermediary is with them from contract through closing with them and the other closing entities.