Usually yes but it depends. If you have a legitimate reason they are usually understanding and can delay you to the next intake. Though depending on the university there is only 3-4 intakes a year, so you might have to wait until January.

It is not a disaster, it is a typical PhD. I would focus only on finishing, don't worry what your supervisor thinks as the only things that matter are you submitting and passing. She will want you submit as a late submission is far better than no submission, especially if she has a history of it.

The real question is do you need an extension to write up or get data. If it is to write up, make a realistic plan and propose that to her. If you have only shown her one chapter, she probably knows you will need an extension and having a plan shows maturity.

Take a break. Working weekends quickly leads to burnout and you end up under perform. I know it is tough but I also had to learn the hard way, that hard work does not always equal results. You might be under preforming due to the burnout and a break might improve your results.

Also I wouldn't judge your lab mate that much, we all work to different schedules. It is not your job to report how much time she is in the lab. If you are getting on well don't ruin by getting involved.

I am in the same boat. Supervisors don't know my methodologies and think all my data is amazing, even though just replicating another paper. I have had to teach myself everything and my motivation is patchy at time (procrastination is my best skill).

However I am enjoying the freedom. As PhDs vary significantly and this kind of supervision can be quite liberating if you know what you want to do. As my supervisors don't know my methodologies I can spend time doing my own experiments. The project has changed significantly at my own discretion with no problems. I had serious problems with my fear of failure but realized it is my PhD.

What I am trying to say is don't try and change it but embrace it. You can take charge of the project and no one will really care.

Talk with a visa expert, they will give you far better advice than us. Not to be rude but did you over stay your previous visa?

For some reason the government cares about people leaving at the end of their visa. If you have stayed longer or worked on a tourist visa, you might be considered a high risk.

I didn't do a presentation on my experience but on my draft proposal. However you could focus on transferable skills you gained from the Msc and how you did things instead of what you did.

They also love it when you explain when things went wrong and how you solved that problem.

Don't get me wrong posters can be god but I been rejected by so many times I just want an oral. I think posters are great if people visit them but I have been to a few conferences recently were I shouldn't have even bothered. At the last conference, I was in the back corner of the poster room behind a pillar. Again they can be just as good of an oral if some people read your poster.

It is a negotiation, someone has to compromise. I would make sure that the contract ends in June as you can then treat it is a 10 month contract. If he doesn't budge just say you need think and say you are looking at other places. Sometimes that gets them to compromise.

Is it a small journal, in which case it might be due to holidays. I just submitted to a journal and got an auto reply saying to expect delays due to editor absences (only three editors).

The other option is that the two reviewers gave very different decisions and they are quickly asking for a third opinion.

Be honest and professional about the reason why your left. Explain why it didn't work out and what you could have done better. You could use one of the typical reasons for leaving normal jobs as they are similar. Most people are generally accepting of you leaving as long as you can give a coherent answer. But I wouldn't bad mouth your current supervisor, university or project.

This person had a successful experience similar to yourself
https://www.postgraduateforum.com/thread-55637/

The document probably also states that the studentship lasts only three years. Charging for extensions is pretty common and allegedly pays for your supervisors time and other stuff.

2 years is a long time waiting and I can understand your frustration but you don't need to do a PhD right now. Getting a "typical" job does not rule you out from applying for a PhD in the future. Sometimes 2-3 years in industry can bolster your CV and make you a better candidate. There are plenty of PhD students who start later in their careers and there is no shame in that. I think you should do what is right for yourself.

It is like any other office job, 28-35 days holiday a year or something like that. They can technically take it anytime of the year but are under pressure not to take it during term time.

PS: not a lecturer