Are there any red flags I should be looking for while I am talking with the various individuals and companies?

Just more and more useless red tape to place bandages over already healed wounds.

I'm actually driving through Redding right now on my way North!

As you know, Brooklyn is red hot so I only expect things to go up.

I’m imagining that not too many banks are going to keep rolling out the red carpet for Gabe and saying, Sure, we’d be happy to give you another $80,000 mortgage (assuming for that he’s buying $100,000 houses with a $20,000 down payment).

Having worked with Australia investors for a few years now sometime I feel like I have a white shirt and red cross on my back sometimes lolThe prices that some foreign investors got spruiked into buying is just insane.I believe if you can assist your acquaintance friend by spending half a day doing some research on the wholesalers and other real estate professionals in the area that might be able to assist with the sale of this property.You can also put a few adds on Craigslist and see of you get any bites.Thanks and have a great day

Also requirements they look for and things I should look at as red flags.

For me, this would be a red flag.

One of the biggest red flags from some TK providers is the 'need' to put +10-30% over the appraised value to purchase the property.

However, like @Ryan Steele said having that extra layer of protection, which may protect you (and actually a newbie rehabber using an irresponsible GC), may dissuade them from borrowing money from you as it is a bunch of red tape that requires time to cut through.