[*]tried to pay of that bounty at the same faction that issued it: possible but..hey...interstellar factors...
No, not possible. You cannot pay off your bounty anywhere else but at an Interstellar Factor. Only fines can be paid off where they were issued. If it's a bounty, you can only hand yourself in, but that will result in being transported to a detention center, sometimes many lightyears away (strange, apparently there are no prisons in every star system), which is nothing more than an extra annoyance in most cases.
The system is pretty counter-intuitive, especially if you are not playing a criminal character and only accidentally became wanted for a measly 200 Cr bounty on your head, which you got for an unfortunate shot causing nothing more than some insignificant damage.
There are several documented cases of people getting stopped by a police officer for driving too fast or having a broken rear light on their car, and getting shot because they didn't put their hands on the wheel or tried to grab something from the backseat, with the officer getting nervous because the thought they'd grab a weapon.
No, that's only the US. In many other parts of the civilised world (like in Europe) there is literally zero chance that you'll get shot in the head by the police for not placing your hands on the wheel or something like that.
That said, I agree that the OP did many mistakes, it's just that the ingame C&P system is very stupidly counter-intuitive in some cases IMO, so I wouldn't condemn him for not being able to guess what consequences he might face, based on RL experiences.