Am I obligated to let them know of my intent to sell?

Intent is to replace one 5 ton AC now as well as ongoing service repairs for other rental HVAC equipment.Thanks,H.P.

My intention was to get information on a current project I'm working on, but I walked away with so much more. 

I bought a house at a tax foreclosure auction with the intention of fixing it up and moving in with a roommate once it is finished.

Your tennat agreed to the rules when they signed and if you have no intention of enforcing your lease you have no reason to bother having a lease. 

They used the $125k as part of a down payment on a new house with the intention of selling the original primary residence then paying off the HELOC.However, the original house has been on the market for 3-4 months and not getting much buyer interest, while costing a lot of money (double mortgages + heloc).

I have a property currently under contract with the intentions of doing my first BRRR strategy and turning it into an AIRBNB/vacation home.

The intent behind that is to verify that you're getting paid, you're not on any type of probation, and you're not likely to get fired/demoted.

Fraud has to be intentional right? 

I don’t think his intention is to create a loan.