The roof is nearing the end of it's life anyway, so we figured it doesn't make sense to patch it, only to replace the roof not too much later.

If I were you, I'd have a foundation repair company give you a quote during the option period and then ask for that amount off of the asking price, or even a couple bucks more to account for the hassle and patching cost.

It needs a little work to pass appraisal and underwriting - furnace repaired/replaced, few pieces of rotten trim, maybe a roof patch, septic pump per county requirements. 

One question I have is what draws investors to use companies like Peer street and patch of land instead of going directly to the hard money lender themselves?

Check out callrail you have to pay, but you can set up multiple numbers and have it say which mail campaign or number the incoming call is from prior to patching through the caller.

Hedge funds should have their money out of (or moving out of) real estate and into the oil patch.

I have used Patch of Land from a recommendation on Bigger Pockets and they worked well for me, but my strategy is flipping and buy and holds would warrant different kinds of financing.  

(New carpets, painting, patch that nasty cosmetic whatchamacallit, etc.)I usually try to get 25% of the price as gross potential profit for my investor, and I charge a 6% assignment fee based on what the seller makes.

As I mentioned, they patched around the shower.

and I'm choosing to interpret that as you hit a rough patch and jumped immediately into looking for help.