Regarding materials, it's not just the units.

As a GC I can advise try to retain control of your finishing material orders (anything where you need to make a choice ((tile, flooring, lites, faucets, tubs)) vs. construction materials (2x4s, mortar, shingles)) because we get those discounts on the finishing items and we keep them!

What information or materials would I need to file one?

Even if the bias isn’t political or socio economic, writers NEED something to write about, and if there’s no new and thought provoking change in lifestyles, let’s promote one we want to be true.  

Not saying I would abandon this if I can't qualify for the material participation, but it is a factor.Any input is much appreciated!

The labor and materials cost varies widely in different markets.

An idea we have is, I am burnt out from W2 life, and wife makes great money (+$300k) , and I could take the year to repair/renovate, manage, rent, repeat the units in the MF qualifying for REPS status (50%, 750hrs, material participation, etc). 

"We are sorry that we cannot continue this insurnace therefore your policy will not be renewed...Material increase in hazard as evidenced by the fact that the residence is not owner occupied as required by our policy".

I am wondering if anyone would recommend any real estate investing courses, podcasts, books, or any other educational material that has helped them in their own career? 

Compared to pre-TCJA rules, there is no material change in the tax treatment of a building involved in a like-kind exchange, where a cost segregation study has been performed.