I highly recommend maintaining HVAC, plumbing, and electrical outlets.

I excluded all expenses including taxes, insurance, HOA, 10% vacancy , 10% Maintainance, and 5% capital expenditure.

So to your question, yes, units with new stuff will cost less to maintain because they tend to break less and you have longer to budget for total replacement.

You can make a deal with your broker since it won’t be your main career, and now you have data that you not only get for next to nothing, the money you save on realtors covers the cost of getting and maintaining the license.

Getting some bids (for example, it needs the asphalt driveway replaced and a 25' x 4' retaining wall replaced (currently rotten wood, replacing with concrete blocks/stone face) but hard to know exactly how much $ the repairs would cost (and what he's willing to cover). 

The first pillar is avoiding unnecessary and risky activities (don't drink and drive, insurance generally won’t cover your poor decisions) and take good care of your investments(maintain your property, etc) - these simple steps will help you prevent lawsuits before they even occur.

Tenant shall maintain the Premises exterior including the entire lawn, front and back free of debris so as to maintain same in a neat appearance.

It's more of a concern for him maintaining his tax advantaged status than anything.  

Or are they actually proactive at enforcing your lease and maintaining eyes on your property?

MLS fees, board fees, license fees, sentrilock fees, e&o insurance.....it adds up to thousands per year to maintain your license.