As for Cash flow, I think it depends on the deal structure as you mentioned, but also strategy/approach (cash flow vs building asset, holding long term).

The #1 determinant is the Tenant Pool.If you don't believe us, try putting several Class D tenants in Class A apartment buildings and watch what happens.

If any one can recommend a good REI focused lawyer or a building engineer to do a building survey then please let me know! 

Its not as easy but once you are up in running you are building a brand, equity in your business, and also constant flow of leads.

Depreciate 75% of the building value (excluding land) over 27.5 years for significant tax savings.

If you have the sellers, the buyers will start reaching out - it likely wont work for some of them and then you can ask what they are looking for and build relationships that way.

I leveraged my owned land to build my personal home.

This has pluses and minuses.If your property is bulletproof such as no framing - cinder block construction, cement floors, gloss white paint slapped on the walls and a cheap window mount AC, then you are in a prime position to make money with S8. 

Also, I'm a civil engineering expert in Building Information Modeling.

A lot of people who househack do so as a basis for a strong financial future and to build generational wealth and financial freedom.