Most buildings of this size would be 45-55% depending on a bunch of factors.

Do you know of agencies/institutions that have influence over lawmaking?

Factors for this are they are passive and notes are typically considered ordinary income so better tax advantageWhen buying property you have to be careful of leverage and UBIT as well as you lose the tax benefits associated with it as well since it’s already tax deferred.

I discuss these factors in a YouTube video. its very similar for acquiring distressed assets, need your team in place and show you can close quickly. thats what brokers want. https://www.youtube.com/watch?

This could start out as a qualitative factor, but can quickly become a quantitative factor. 

Since I don’t have any experience yet I want to build good habits and thus have a better chance at building great relationships with contractors because I understand that’s an important factor in being a great real estate investor.

Or, a $500k house in the midwest or somewhere like Georgia will be nearly a mansion, and that high of quality of property isn't likely going to have a very high rentability factor because it's too nice... people in that arena will just buy.- what's the rentability factor and what kind of tenants will it attract?

Depends on numerous factors including rental income as well...Best to have this discussion with your cpa

What factors do I need to consider with a strategy like that?

Overshadowing all of this is a tendency for lenders to hunker down and be very selective and conservative in underwriting and issuing new loans, so that is another factor to consider.