This way the partner is getting paid more precisely for what they contribute.

Looking to have access to more capital to help do more deals this year and want to make sure i'm not breaking any laws and get into trouble.  

You can't actually pay it off directly because they've been securitized, and the people who invested in those securities did so because of the specific certainty of the payment schedule.What you do in a defeasance is use the proceeds of the sale or the funds from your new lender to purchase treasury bonds that are packaged to make the exact payment amounts and timings on the remaining term of the loan, and then assign those bonds to your old lender.

This allows me to tune pricing after spotting trends. 

Use the HELOC on cash-generating opportunities like flips, then use the cash generated to buy long-term buy and hold investments. 

Do you have any experience using a piece of land as collateral for a construction loan?

If there is equity can you use that to reinvest and come out better ahead doing something else?

Here’s our OPINION for the Metro Detroit market (use as a template for your target area!)

I never heard of this before.

As explained in this article, seller financing works best if you understand the needs of the seller.https://www.biggerpockets.com/blog/seller-financingReally dig into this topic and ensure you understand it and are prepared to use it.