Use a bank.Also, look up "release fee" a stated value for each property to be paid in order to release that property, otherwise you may not be able to sell if you need to. 

As the investor/lender I would want to see lien releases from all subcontractors with each draw request along with proof that the work was completed through requested draw. 

I do not know much about the market but higher end rentals generally take a bit more time to get released because there is a smaller pool of renters who can afford it.

Do you allow for partial release clauses?

I'm not sure if you can work on a site as a volunteer regarding having workman's comp covering you.Insurance may dictate authorized personnel only.You need to know about getting utilities stubbed in, framing terminology, a good on time on budget electrician, plumber, all trades and an accountant for taxes and bookkeeping (as you don;t know how to track the house costs on the books for when you sell).Lein releases for your area, good subs from flakes and poor workmanship subs, and etc, etc, etc.You will not learn this in a week, but a few weeks around the construction site and youtube research might be useful---just don't ecpect the workers to take time to chat with you and teach you--they are there working hard earning their daily bread (beer).Good Luck!

Also, there always needs to be some level of consideration in any agreement, so not a bad idea to incorporate a general release in the agreement as well.

How would you go about releasing an existing memorandum from a Buyer that never performed?

He made me sign a contract that effictively states, "forfiting of earnest money does not release you from the contract, and you can still be forced to close".

Just go for it. the fear in your first deal will always be there, but you have to move forward cause you cant steer a car that isnt moving. you can turn the wheel for hours in the driveway and plan your rout but you have to release the parking break and start going. even if your in reverse, at least you know your first step is to change the direction of travel. but in the driveway, with the break set, all the steering and gear shifting and analyzing wont get you anywhere. pop that clutch baby!

For example at Castic Lake they use energy that is delivered when not needed to pump water up in the lake, then when they need that water it spins a turbine as it flows down, releasing that stored energy.