@Austin Dame
I'm currently house hacking a 4 unit similar to you and its my first investment property.
1) Do you need to sell your current place? Can you turn it into a rental? And is it THAT obscure that nobody will buy it? You bought it so there's gotta be someone else out there interested.
2) Is it the end of the world that a tenant doesnt accept a buyout? I inherited 3 tenants and I've been blessed that they've all been great. They've helped offset my costs while I'm renovating the other unit and figuring this thing out. I have kept them all up to the end of their lease. I'm renewing some for the next year to keep cash flow and terminating others.
3) I'm not licensed or have extensive knowledge on the mortgage side, but it doesn't sound like you're committing fraud. You're legitimately intending to move into the place as your primary. Why the distrust of the mortgage lender?
4) This could be a big deal with your business. I'm not sure what your business is, how often clients see you, how big the demand is that they travel to you, how much of a change it is for them, and if there would be new clients in your new area. My wife runs a specialized personal training gym and her location and convenience to clients is very important, but she also sees people multiple times per week and she could get new clients in new areas. You can probably get a feel for it from your clients by giving them really clear communication. They will complain but most of them adjust pretty well after a bit.
5) It sounds like you're also putting yourself at a lot of risk financially. If you're putting everything you have into a non-expensive property (possible read as a run down or lower classified), you may find yourself even more financially extended when stuff breaks down or repair/renovation costs.
6) What is your plan on what to do with the unit? It seems like you want to raise the rent since you're wanting the existing tenants to leave. Are you doing a renovation? how are you financing that? I'm not sure if you're planning on doing any of the work yourself, but if "way too many stairs" is damaging your health, you should probably steer away from self-renovations.