If they have a lease, they get the benefit of the duration of the lease (Assuming its a legitimate lease).

For our primary mortgage, we are 2 years into a $600K 30 year 3.75% fixed conventional loan.Here are some pros and cons I can think of for each option:Invest as CashPros:Very liquidLess riskyNo interest on cash amount for next investmentKeep higher primary home interest expenses for tax write offCons:Sits in savings account earning 1% until reinvestedPay Down Primary Mortgage and Take Out HELOCPros:Saves $275,000 interest and reduces payoff during to 15 year on primary mortgageCons:Puts primary home at risk if future rental property investment goes badHigher and variable interest rate on HELOCBanks could close HELOC at any time removing my access to the funds for investmentMiss out on tax benefits of higher primary home interestUltimately, our goal is to have no personal debt including primary mortgage, while building a steady stream of cash flow through rental properties over time. 

If you're self-employed, the Solo 401k plan will likely work better for you.A few Solo 401k benefits: Compared to an IRA, Solo 401k contributions limits are roughly ten times higher.There is no custodial requirement for the 401k.The Solo 401k can allow you to borrow funds from the plan, unlike with IRAsYou don't need the additional expense and administration of an LLC to have checkbook control.There is a built in-Roth component whereas IRAs are either traditional or Roth, not both.A spouse can also participate in the same Solo 401k plan.The Solo 401k has additional tax benefits over an IRA when investing into real estate using leverage.

Is there a lot of benefits in integrating a construction company into a real estate company?

I think it will potentially reduce my total cash flow, but I’ve adjusted my marketing to compensate for the added benefit and disadvantage of having a live in property manager.

I do suggest you learn about your VA loan benefits, i'm not sure how the eligibility works for guard members.

I have researched through benefits and downsides and even with taken the cons into consideration, it seems to like a great deal. 

You have to wait until you sell the house to get a benefit of the interest expense. 

So the monetized installment sale would be best only if:a) the seller wants a simple cash exit without paying capital gains tax (until after 30 years)b) you can line up your own purchase financingOr, maybe the seller would benefit by using this approach to dispose of other properties they own that are not the ones you wish to buy.

Even though it was a pain to get it wrapped up now you can benefit from it for who knows how long!