Your 2:2 is certainly a problem both from the perspective of getting accepted onto a PhD course and also your ability to cope with the PhD successfully. A postgrad masters degree is the easiest way to fix that.

People do get onto PhD programs with a 2:2 but my personal opinion is that this simply devalues a process which should be preserved for the most academically gifted people. The PhD is the pinnacle of academic achievement. Preparing your base camp properly with a good masters degree is commonsense really so I think you have the right idea here.
You should experience no problems whatsoever getting onto a Masters course as far as I know but oers may have a different opinion.

Go for it and good luck.

It sounds to me like you are making the classic mistakes of both setting your expectations too highly and chasing impact factors and publications instead of focussing solely on the research. The former follows the latter.

I would take a step back and re-evaluate your approach and expectations of your career at this point. If you focus too much on the ends you risk destroying the means.

A postdoc is no different to industrial employment. In both games you need to achieve measureable success or you will struggle but if you continually try to visualise "lifting the cup" (as advised by bogus "motivational coaches" everywhere) you run the very real risk of psyching yourself out and being knocked out in the first round. Focus on the day to day stuff and set smaller targets. You should start by recognising that your PhD publication record is now irrelevant to your current situation. The impact factor thing is certainly not helpful right now.

Minor changes means the external doesnt need to see or approve your changes.
Simply argue away the things you wont be changing.
I didnt change every single comment either. I suspect most of us will do the same thing.

I am a little confused here.
Why would you think it was your supervisor's choice what job you took and when you took it?
Just accept the job and let your supervisor know you will be leaving on a specific date. Do the thesis changes in your spare time.
Absolutely no reason to feel trapped.

Look into current jobs for data analysis, figure out what skills are required and set about acquiring those skills in your spare time.
Once you feel you have some competence then start applying for jobs. That is how I have operated in the past.
You may already have enough skill anyway. Nothing is lost by sending in a CV to a few jobs and finding out.

For me it is about moving on with the minimum of fuss. Other people have a duty to fight their own battles. I am responsible for myself, my own future and my own mental health. Usually there is an opportunity to explain to someone more senior why you are leaving and I have always taken the opprtunity to do so in an assertive and crystal clear manner without letting emotion get in the way. Whether they choose to act on that is then their decision.

Of course it depends on the extent and nature of the bullying. For example, I would not allow sexual harassment, which I had personally witnessed, to go unreported but make no mistake, I consider the impact on myself first and foremost.