Oh boy. Here we go.
I don't know how much "research" you did on fuel pumps for minis, but I guess it wouldn't be much. If you did research, you would have found out that the hpfp you replaced is under warranty for 120k miles through mini. It would have been free. Good job on your "research" .
While you were replacing that hpfp, did you at least see if you're getting fuel to the hpfp? Crack8ng the supply line to the hpfp open would tell you if the lift pump, aka in tank pump was working.
Here's a little hint. Di bmws will idle and drive with a bad hpfp.
Pick up a reader, I recommend Carista for BMW vehicles. Run the codes before you dump anymore cash in it.
If you live close to or in New Hampshire, I'll throw you some cash for that car. Better than you burning it. After you sign over the title, I'll clean the grounds and drive it away.
Be it a BMW, vw, Ford, Chevy, etc, these newer cars ain't for people that can only work on old school cars. It takes more than parts swapping.
Pick up that carista obd2 reader, post your codes, forget about the dumb ass "spray starting fluid" comments you're getting here.