Does not mean they do not exist but it feels a bit like looking for unicorns.The more likely scenario is finding a 3/2 for $2,500 a month that bring in $5,000 a month in revenue. 

In all of these scenarios, I kindly replied "Sorry, no vouchers", or "I'm sorry, we're not accepting vouchers at this time".

Can anyone with knowledge of bonus depreciation weigh in on a scenario I’m piecing together?

In this scenario, you have to make sure the house conforms to VA guidelines in regards to its condition when you purchase. 

However, if my old college friends want to live with me and help with the mortgage I thought it to be a great house hacking scenario.

Noted on the units too, ideally a nice 4plex would be the best case scenario but as you mentioned anything is better from a financial perspective than paying the amount in rent I am currently.This market could cash flow pretty well at 20% down if i find the right property as the prices are below national average and rents are actually fairly good in comparison to property prices (plenty of 1% opportunites on SFH with a minimal cosmetic TLC). 

.), would a 50/50 profit sharing scenario be common/acceptable?

There are a lot of issues with having JADU including finance issues if there is also an ADU, requirement for owner occupancy, that it removes space from the primary structure and usually lowering the value of the property such that it is common practice to remove the JADU when selling the property.  

With my experience with very wealthy individuals who have complete freedom of time, one common denominator is: Keep it simple and a little boring. 

Common fees will include a set-up fee, a leasing fee for each turnover or a lease renewal fee, marking up maintenance, retaining late fees, and more.