...and my bike backfired without pressing the starter.....
how can this be? surely to backfire something must have combusted... meaning a spark fired without any engine rotation triggering the hall sensor... dodgy coil, hall or wiring?
I freely admit to not knowing a huge amount about the oilheads (my own included) but as I understand it the hall sensor tells the coil when to fire and also the injectors when to inject. With your fuel pump always on and the lines pulsing suggesting theres fuel being pumped to them, I would have the front cover off and check that your alternator belt hasnt shredded and taken out the hall.
as other have said i wouldnt be happy with that battery connected *at all* until youve found the culprit.