I have three rentals with a pretty good amount of equity and I would like to tap that equity while I'm paying the loan down and increasing my equity as efficiently as possible. 

That's awesome you have been able to increase the rent rates beyond expectations, secure an off-market deal, and leverage yourself as an agent.

There would be somethings I'd like to just mention to them to see if it would help increase their business, but otherwise let them grow and we just have a percentage.For example, this could be part of the structure.

Be extremely conservative - assume very low rent growth, very low appreciation, and fairly stagnant interest rates, meaning minimal opportunity to increase cash flow through a refinance. 

Hi Travis, You absolutely could increase your renovation sending.

Is there any room to improve your current rentals and increase rents?

Your landlord could increase your rate at the next renewal, or your landlord could sell and the new landlord could renew at the market rate.The sooner you begin house hacking the sooner you'll find out if real estate is the path for you.

However, you may also be constricted by DTI requirements, as DTI increases as you obtain more properties.

However, over the past five years or so, increased national attention has led to a surge in supply, thereby putting pressure on occupancy rates, which might hover around 50% annually.

For the back unit, increase it a bit once the lease is up (eg $50 a month).