I understand your position, as I have experienced a somewhat similar situation in my parish council. The first thing to remember is that, as a parish councillor, you have the right to express your views – indeed it is your responsibility to do so. Parish council meetings exist so that councillors can discuss matters, everyone giving their own opinion. The Chairman’s role is to chair the meeting, which means giving all councillors an opportunity to have their say. The Chairman’s opinion carries no more weight than any other councillor’s.
In your position I would approach the Chairman outside of a meeting and say that you would like to talk to him. At this meeting with him I would say:
'Can you advise me how I can make my views known at Parish Council meetings? At present I find it rather difficult. I get the impression that meetings are tightly controlled, and so I am finding it difficult to raise matters. When I do raise matters, I feel that they are not taken seriously.' If appropriate, you could go on to say that you find the Chairman’s style of running the meeting domineering, and so you are finding it difficult to contribute, Get him to agree that it is the purpose of the meetings to allow all councillors to freely give their views and opinions. Similarly on the question of agendas: say that you would like to suggest agenda items. Does he agree that he is quite happy for you to do this?
Remember: you are quite entitled to say all this. Remember too: it is more effective to use phrases expressing how you feel, e.g. ‘I get the impression that ..’ or ‘I feel uncomfortable when …’ etc rather than to accuse the other person directly of bad behavior, which immediately makes them defensive. Engage them by asking how they can help you overcome your problem (which of course in reality might be their problem).
On the question of minutes: presumably the PC meeting approves these. If they are not accurate, you will just have to pluck up the courage and challenge them Maybe do this with the Clerk when they are circulated before the meeting, and point out errors and omissions.
Presumably you have Standing Orders and other relevant policies. When these are not followed, again you will have to bring this up.
If you are a lone voice on the Council, I understand that you have a difficult task ahead of you. One thing that might help (again from my experience) is to persuade local residents who are unhappy with the way your Parish Council is run to attend meetings, and express their views about it.
Finally, and I acknowledge that this might not be appropriate but I hope that you don’t mind me suggesting it: consider getting some assertiveness training. Practical training would be best, but a check online provides some helpful websites.
Finally: I am sorry that you are in this situation. I get the impression that this is not uncommon in Parish Councils, and it has already been noted there is no regulatory oversight of PCs, unless they do something really bad! The real answer of course is an engaged community who take an interest and care how their village is run.