Explore alternative options like hard money loans (fast but high-interest), seeking private investors, or obtaining a business line of credit if your business generates income.

BookingPal is also a great Channel Manager, alternative to Rentals United

Alternatively, DSCR ratios may not work out due to efforts to maximize the loan amount and avoid additional cash contributions. 

value adds, flipping, alternate rent models such as STR, MTR, rent by room  can help with the return. 

Alternatively, what's the best way for my friend to get their funds back without any tax implications (if any) for him and business?

In six months, you will have done more research than most on these two alternatives, and you will have your answer. 

This way instead of filing Schedule C for the LLC it will file it's own tax return separate from yours and will issue K1 for both yourself and your spouse.An alternative to that is you can hire your spouse to work for you and pay him salary.

If you read up on it minimally, you would probably come to the conclusion that it makes no sense to pay someone to do what you can easily (and cheaply) do yourself.I recommend this, not because it's better than REI, but because (1) it is an alternative and/or (2) it is a pretty decent place to leave your money while you wait for your next deal.  

I have arrived at forex and real estate.

I overwhelmingly support alternative building methods, but there's generally a reason that they stay alternatives and never make it mainstream.