@Sam Rane Hi Sam! 1 & 2) I personally love the Oklahoma market lol! But seriously, like @Scott Swanson said, any OOS investing has risks (heck for that matter something next door to you will too, but you know that), but having good contacts helps mitigate the risk.
3) Under $100K...that's tough, you'll probably have to go outside of the major metros. Rents and rehab will be your challenge. How much do you have for rehab? Do you want a major rehab? If not, I would raise your min price range a little bit. It's so subjective (what someone considers major vs light rehab, and the areas you could buy in) that it's hard to nail down a specific number for you on that without narrowing down several things.
4) Depends on where you are looking. What type of renter are you targeting? College student? Military (we have several bases here)? Family looking to get in to a good school zone? Downtown denizen? Condos, Apartments, SFR?
5)If you do get an LLC (I am NOT an attorney, please consult your attorney for advice), look into getting one that is registered in Oklahoma. There were a couple of BP podcasts recently that covered LLC's, look them up and listen. That guy was an attorney and had great advice!
6) If you are not going to self-manage - yes you need a PM. I have a few that I can give you if you want to call them and see what they offer.
Welcome to the BP Forums! What makes Oklahoma interesting to you? Do you have a connection here, or just looking at different areas and we popped up? Set up some keyword alerts on here to notify you of topics you are interested in (for example: LLCs, newbie, property manager, Oklahoma). Good luck!