what's to stop them if I'm at work or short vacation and someone breaks in and claims it as their home because " a PM rented them a furnished place ?"

In this case you'd either need to pay enough to pay off the mortgage--in other words, pay full price--or pursue a short sale.  

Try an asset based lender for a short-ish term (3 years usually).rate will be higher, but it'll be an easy loan to get with almost no underwriting.

I've been watching HGTV at home, I've also watched The big short (a movie about the 2008 house market crash), and also got an few books that I haven't gotten a chance to read yet.

I'm finding the hard part is more finding properties that are in a good location and also don't have restrictions on short term renters (either hoa or local regulations).I've reached out to owners with the same basic offer (increase rent, cover repairs up to a certain amount) and most people are hesitant to even discuss it, so i think it's a sheer numbers game and being ready to buy a property when one shows up that matches my criteria

You will have a very short period of time between the students moving out and the new ones moving in each semester to get all of your repairs and cleaning done. 

If you're in the short game trying to capitalize on market fluctuations or appreciation, the risk is that you might buy at the top of the market and get stuck overpaying with few exit options.if you're playing the (really) long game, then it matters much less.

The loans are usually short term (6 months). 

If you had a short term, hard money loan that you could refi out of, interest rates might be up to 5% in 6 -  12 months (seasoning period) anyway.  

This was when I purchased my primary residence through a short sale back in 2011.