If you buy a 2nd position you are buying subject to the senior lien; If that lien is in default then the total payoff ( if in default or foreclosure, interest, late fee's, foreclosure fee's, etc. ) is still owed and secured on the home. 

What would your total monthly mortgage payment be? 

Totally WRONG.

As an example there is/was an estimated 3,000,000 SF of industrial space occupied by marijuana users in Denver out of 300,000,000 SF total. 

For a 16ft (4 - 30", 1 36"sink,1- 24" DW,  1 30" microwave cabinet. 2 - 18", 1 30" for island (10 total boxes @$400 each installed)) of counters/cabinets, I'd expect a $6500 cabinet and counter budget which includes sink and hardware.    24sf of cabinet counter + 12sf x $40/sf budget placeholder is $1440.  

Do not rely on it for legal advice.

TOTAL PROJECT/CONSTRUCTION COST $25,000,000LAND COST $ 3,000,000 (CONTRIBUTED BY US)TOTAL EQUITY (INCLUDING LAND) $ 5,000,000CONSTRUCTION LOAN $ 14,000,000MEZZANINE LOAN $ 6,000,000The developer is getting a fee for the project.

How do I go about ensuring that at the time of closing, the total cost of fixing plus my fee for the fixing and coordination gets into escrow and I get pay out at the time of close and my brother only gets the remainder from this sale?

The debate going forward is continue using my own cash (in total control, no interest, can make more competitive offers to acquire properties, higher $ amount returns, no contractor draw requests/inspections to deal with throughout entire project) or turn to a HML who is going to cost me around 10-11% with 2-3 points interest only loan with no pre-payment penalties (much less cash out of pocket, high cash on cash % return, potentially do multiple projects at once). 

As someone who likes to be conservative with projections in all other things I do, I totally understand the conservatism here.