This would be my first crack at a mid-term rental.I've got a property that I'd like to rent mid-term (30-90 days) to increase cash flow compared to a 12-month rental.

I like @John Underwood idea - turn off the utilities and call the Sheriff.And once the house has been cleaned up, get a PM company to run this for you, I don't think you have the right mindset for this, and you can't have your son run this forever, right....?

Recently bought my first foreclosure, rehabbed it, currently house hacking, living for free, and making $400 in cash flow. 

Strategy will also help you identify specific goals, such as cash flow, appreciation, and so on. 

If that’s the case, and you have an enemy in that small a group, your path of least resistance may be to reset and try to get some empathy flowing your way.

Utah is a hard market for long term single family rentals to cash flow, so it's been difficult so far.🏠 I got interested this last year after my parents had to move again from their rental, as the owners decided to sell.

We do have a decent amount of equity on the home about 150k (current estimated value is ~315k) but since the mortgage is 15 years (which I thought was smart & would save me interest over time...) if I were to charge market rent I would break even or possibly lose a little and get no cash flow.

Remote can be...Marketing, Lease Signing, Lockouts (install coded smart doors), background checks & screening, Virtual Tours, Payments (online or ACH debits)Live In Person (local team)...Showing units, Posting Notices, Evictions, Dealing with Complaints (some need live interaction), Maintenance Calls, Property Condition Tours, Meeting Utility Companies, Meeting Contractors, verifying Contractors work, Live personal touch with residents (can improve tenant relations depending on property), Cleaning, Turns, Police CallsThrough the years, I've learned that there are places to save money and places to invest. 

I would like to take over the 380k mortgage at 3% and pay the difference in cash, then I still have positive cash flow when renting it out.

I would keep going in that direction and enjoy the positive cash flow coming in.