@Mike Bianchi I would diversify it this way since you are young. 1) $300,000 into a variety of private real estate syndications more weighted towards multifamily but also including self-storage, industrial, and maybe mobile home parks.2) $100,000 into a debt/note fund(s) where you would get a more fixed return.

Ask away...But yes... if at the end of the year you have 10,000 of income in excess of all cash expenses (principal doesn't count) you will then get one last deduction of depreciation and generally speaking that will be the taxable amount.Sometimes if an investor has one property that is a home run and they know they will cashflow well and end up with a substantial tax burden at year end they buy a second property that "loses" money on paper to offset the taxable gains from first property etc.

Rent control reduces available inventory and thus excess demand spills over into the non rent-controlled market, causing an increase in rent and thus an increase in property value. 

This is a little excessive and could be narrowed down to 35 feet, they just have to come around the corner a little slower and you need heavier Bollards on the building corners.

This is the strength of the concrete and how much surface weight it can take.

Our thought was to use a HELOC to fund another purchase, and then excess cash flow from the new purchase (as well as current properties) will pay down the HELOC before the variable rate is a problem.

Having an investor with a huge chunk of the deal or large sum of money invested, will often times have that investor inserting himself in the deal, insisting on having his opinions heard, and pushing his weight around, which will have you feeling like you work for him.There's no right or wrong, but pros and cons you'll have to weigh on your own.Good luck!    

This approach will be a long process to study hard, work hard, and learn to be a skilled and active RE investor, and there is money to be made well in excess of those other more passive forms, but the analysis you are attempting to run on the average numbers for any market will not tell you that, you instead need to find those succeeding in your market, how they are succeeding, how they are analyzing deals, and then find and analyze specific deals.

It had a sag in the beam that was repaired (unsure when) as a result of heavy snow adding the weight from the roof.

That is usually handled through the Excess/Surplus Lines market (your agent will know what that is).