My recommendation here: Walk on this one and cut your teeth on a smaller deal you can afford solo(to build experience+credibility), or work on finding an experienced partner who can lend support to the deal.

What is meaningful to me is ROI because it allows me to compare returns on my invested cash vs. other investments (i.e stocks, bonds, reits whatever).  

He doesn't invest in REI, stocks, bonds, etc.  

That happens later on when I get their financials and after we've had a chance to bond a little.  

Items likely to consider.1) Max buildable interior space allowed by code2) Max number of units3) Max building height4) Utility hook fees and process5) Engineering requirements for foundation, framing, sewer, electrical6) Average cost to build from at least three different builders7) Insurance requirements8) Liability requirements9) Bonding requirements (your builder's should know this)10) Efficiency rating requirements - determines windows and insulation products you can use.If you answer all of those you will be in a pretty good starting place.

Capital losses are possible in any investment: stocks, bonds, notes, loans, real estate.

You have an IRA with the brokerage firm and they only allow you to invest in stocks, bonds and mutual funds.

I know a lot that want cash but give sign a contract, give invoice, w9, receive 1099, or are incorporated, of course licensed and bonded, they just want it because they want to pay day labors or get more discount on material pricing.

Stocks, bonds, bank savings, educational plans,  trust funds and foremost in a real estate.  

This is the ONLY way you can really compare putting your money into realestate vs. a passive investment like mutual fund, stocks, cd, bonds, etc.