To qualify for active status on short-term rentals for tax purposes , you need to meet the IRS’s material participation requirements.

Does he qualify on his own?

Also, I am guessing that due to the state of the house, it would not qualify for a conventional loan?

Each DSCR loan is separate and qualifies separately, so one doesn't necessarily affect the other except for the liquidity needed to close since you'll have multiple down payments/closing costs for each transaction.

You can still qualify so long as you have verifiable income.

This is a long revived post- I'll add a little tax pro insight from what's happened in the last 2 years The IRS went from < 100 engineers on staff who were qualified to audit cost segregations to a few hundred. 

The thing I'm trying to figure out is how to properly qualify as a RE Prof. 

Improvements on property you own do not qualify.2.

My suggestions would be in this order:(a) Determine the type of financing you qualify for - this will short cut the process considerably and save time on investment angles and next steps.

An LLC is potentially one minor factor that might contribute to the evidence that you are running your rental activity as a trade or business, but it's definitely not required that you have an LLC to qualify.