The most conservative thing seems to hold on to the house as we are paying down principal and have options if the market does drop in the future.

You need to define the highest and best use that is allowed by zoning and conforms to the current and future land use plan map for the city or county.

Hi everyone, I am here to ask your advice on a very specific situation. I am currently a college student that has completed 2 years of general studies, and will be entering a major next semester my current plan is to ...

You are basically estimating future cash flow at higher financing terms.

My future is real estate flipping houses to pay for rentals multifamily is the path I want to take (4 green houses trade in for 1 red hotel).

Current expectations of future value are “baked” into real estate prices.

That adds another complexity in this estimation and your future property evaluation)So next question is, "what do you do with this tax rates??". 

Scenario A (typical) - $500k duplex-$125k down-$375k mortgage at 4.6%Scenario B (modular financing) - $500k duplex-$125k down-$260k mortgage at 4.6%-$75k HELOC on primary residence-$40k loan against 401(k) (technically this would be $165k down, but you get the point)In scenario A, paying off the mortgage quickly makes zero improvement on cashflow until you pay it off completely, or refinance, and there's no point in that if your rate is locked in lower than current(or future) market rates.Scenario B could involve higher interest rates on the HELOC and the 401k loan, but you have multiple, simple, easy options for increasing your cashflow, and then you don't end up playing as much in the overpriced, volatile stock market.

Stock options, great retirement and good pay sounds like a very solid path for the future regardless of real estate investing.

I plan on investing in rental properties in the near future.