In truth, the selling company knows what they're going to do for rehab, they have streamlined processes and suppliers (economies of scale like this are how turnkey companies keep costs low and make money), so the buyer doesn't actually get a lot of input on what happens to the property.

I graduated from Michigan State University, and currently work at an automotive supplier within their purchasing department.I am primarily looking to share/learn from others, network with investors, develop relations for financing deals, and ultimately scale my business to a global level! 

You'll likely need a list of all materials paid for, a release of lien may be required by suppliers.

I called the granite supplier and asked for a couple contracts they'd recommend.

I may not be in a position to invest in a property right now, but I'm certainly capable of helping scope a rehab/flip job, and I've got trade and supplier contacts that might be helpful.

But here are some solutions, these solutions are only used for worst case scenario:for liens - issue a joint check between your GC AND the sub. in the future clause of a contract, let the GC register his subs/suppliers (http://ownersperspective.org/bim/bim/item/412-joint-checks-and-direct-payments-to-subcontractors-and-suppliers), ask an unconditional waiver during the exchange.

Then she will give me her bid on labor which will include all general materials her team uses and will include travel for picking up all my materials I purchase from various local suppliers.

You should be able to determine if the area has central water; go to the neighbors and determine if the area has central water, if all the houses are connected and who the supplier is, then contact the supplier and see if they service that address; walk the property and see if there is a well head; determine if the area has septic systems or central sewer; if septic system the well should be at least 100 ft. from drain field; there are water sampling labs that will test the water; I would have a full test run including heavy metals.

This is common practice in my non-real estate busness where as a renter of equipment I am required to to list the supplier as an additional insured/loss payee.

I think I am expecting at least 50 years in my market and if the window supplier is still in business they will get stuck replacing them.