I'd assume that they would deposit the $ in their account so bank statements could suffice.

The issue is that if you purchased via a loan in your name, the LLC probably does not provide the protection you believe is should.At your level you can probably suffice with regular property insurance. 

If the agent or seller questions the name on the POF, a simple explanation that you are using partner money should suffice.

Since you'd be occupying the property, any traditional mortgage would suffice whether you go FHA or conventional.

Lenders want to see you have skin in the game and borrowed money for the down payment generally don't suffice making it challenging for they privater money loan to be sent directly to escrow on your behalf.

For the sales/commission based salaried individuals, I feel like their previous year's tax statement should suffice.

An LLC may or may not be the best entity to use and as Jerry stated, a JV agreement may suffice for the first deal to get your feet wet.

I am currently in the process of building two long term rental properties in Pensacola, but they are not sufficing because they are not yet complete.

What you have left is the value that remains available to pay for the land.10 acres is not huge, so a simple application might suffice, when you are doing a larger subdivision, you will work it using DCF.Simple calculation of an example project:Net sales prices of lots, ready to sell quickly, no long-term sellout: say 40 sites at $50k per site=$2,000,000As completed value: $2,000,000Total entrepreneurial incentive as % of as completed project sales price or as % of total investment amount: 25% of SP or 33% of gross investment under the above fictional premise =$500,000. 

A simple PNL should suffice.