No harm, except to his credit.

even if they did, likley no harm at least as I see it.Take the booking and get a great review, pocket the cash and move on. 

Are there trees over the house that could harm to house?

In my opinion if I did something that caused legitimate harm to someone else then I would be at the very least morally obligated to make the situation 'right'. 

People can get harmed and killed anywhere, it just bothers me how he told me all these things right before a deal was in the works. - If you invest into Florida, what are your tips for staying safe as a “landlord” or just in general?

As long as you disclose everything, you should have no problems.In my opinion, a real estate license is helpful instead of harmful.

I personally don't see the harm in getting positive cash flow even if it's smaller because at the end of the day it's still paying down the mortgage.

If it fails then you back out no harm no foul.That may seem unfair to the seller, but it might also result in them being able to sell for a higher price than they could have otherwise.

I'm thinking that there wouldn't be any harm besides maybe following up too much with them if I did both at the same time.

Does it harm your credit if you do more then one loan pre approval at the same time?