Question: can I get a FHA loan under these circumstances & when?

It's an extenuating circumstance and there probably isn't an official rule on the books for such a circumstance.

I believe this puts you at a lot of risk though so generally I avoid these situations by making it pretty clear that the tenant will not be happy in this property because they will NOT be able to party or make noise or do any of the things you assume they will want to do because the neighbors will complain and I will get complaints and they will be unhappy in those circumstances. 

That might mean a parcel I can split off, combining a split property, general neglect, disinterested landlord, etc.

You might want them to notify you in writing just so you protect yourself from circumstances out of your control to remedy a default . 

If anyone can lend some helpful information or describe their first purchase if it was under similar circumstances then I would be grateful.

When I moved into the house as an owner occupier 5 years ago, the tree was extremely neglected, with many dead branches.

You don't need to worry about representing yourself in court; they don't have any excuse for neglecting to pay their rent.

A lot has to do with your personal circumstances and your market.  

I've gone over the calculation again and again and it's solid, even under ideal turnkey circumstances with unrealistic mortgage/insurance rates, the ROI's are negative.