If you really do intend to move into the house for at least 1 year then this isn't an issue for most of the loans I have seen/heard of. Read the letter of the first time buyer paperwork. I bought a house that was my primary at the time. I finished some rehab and after 2.5 years realized I did not need a 4 bedroom 2.5 bath home as a single man.
I had an FHA loan at the time and that was not an issue since I lived in it an it was my primary. When I moved out I turned it into a rental though. Which means I had to pay back the balance of my first time home buyers $7500 I received from uncle sam.
I have heard of people moving into a new place every year to buy on OO rates and loans. I don't see an issue with this if you are actually following the rules.
DO NOT LIE ON FHA loan docs. or any docs for that matter. But if you follow the rules I don't see an issue with using ti to buy a place that you would eventually rent out. I am a teacher and the Good Neighbor Next Door program lets teachers buy HUD homes for 50%. HUD gives you a second for the other 50% and pro rates it over 3 years. If after 3 years you move they don't claw it back. I have looked at this and if anything ever comes up I would want and I get a free $100K to live somewhere for 3 years I would do it in a heartbeat. But I wouldn't try anything over the 3 years.
Follow the rules and make sure you don't get bit in the ***. No one ever expects to get caught. But it happens. Insurance is prob the thing people forget to change that even when done legally can bite you in the *** (forget to switch to landlord instead of OO on the right day and something goes wrong on that day).
Just make sure you follow the letter of the law in this and don't take something in the spirit that could go to someone who is actually in need. If you are gonna move in and live there for the time period and just buy somehting that you would rent later I think you are safe.
Ben