We ran into an appraisal issue and our agent helped us fix it and negotiated a longer closing despite the fact that they initially wouldn't budge.

You can also try the BRRRR method, which involves buying a fixer-upper, rehabbing it, renting it out, refinancing to pull out your initial investment, and then repeating the process.

Money for down for his initial RE purchase.  

I was in the military so initially thinking of using a VA loan.

Here are a few initial questions that I have: - I'm wondering if there's a recommended corporate structure for these type of business activities, focused primarily on both short-term and long-term rentals.

However, real estate offers advantages beyond just the initial interest rate.

Red flags to be aware of: Are there any deal-breakers or warning signs I should be looking out for in the listings or during the initial research phase?

Depending on the initial terms of the mortgage, I'll hold on to it for 2 years and then obtain another mortgage.  

did they lock the loan at initial application, and for how many days?

This will give you an idea of how many pages it will initially include.