do u think many commonwealth nations will leave the commonweatlth when the queen dies and charles takes over?

I think you're confusing the Commonwealth of Nations with the countries that have the British monarch as their head of state.

In regards to the former, I don't believe any country will withdraw because Charles becomes the head.  His appointment was already approved by the Commonwealth countries a few years back.

As far as the latter, there might be some countries that re-evaluate whether they want a monarchy after the current monarch passes.  Barbados is already starting the process of switching over to a republic.

None of the buggers unfortunately they will still be leeches.

A couple of years ago or so HM told the Commonwealth she wanted Charles to take over from her as head of the Commonwealth. It was reported at the time most had agreed,anyway what is wrong with Charles ? better I think than that awful Henry of Wales.

I feel that once Elizabeth II dies there will be a general reset of the role of the Monarchy 

No. The Commonwealth of Nations agreed to have Charles be their head after the Queen dies, already...this doesn't read like any country will leave the organization.

Highly unlikely.  Most Commonwealth countries are republics, so the Crown has little, or no influence on them anyway, but it is good for countries to have friends, so the Commonwealth will remain.

Commonwealth Realms are a different story.  There are currently 16 of them, for which the Queen is Head of State.  There is at least one country in the process of becoming a republic (Jamaica if memory serves), and Australia has at least discussed it.  Other countries, like Canada are highly unlikely to change their system.

 No because there will be no reason for them to. Just because Charles is king it won't make any difference to the Princes Trust.

Most definitely. When the Queen’s reign ends, and after a respectful period of mourning, the Commonwealth realms 

will reconsider their ties to historically-colonial British monarchy. Charles being on the throne will only help expedite many Commonwealth realms doing away with the monarch as their UK-based head of state. In the monarch’s place, countries formerly known as Commonwealth realms, will have their own heads of states from among their populace.  

No I don't. Their membership is not solely based on having the Queen as its head. I predict more non-empire countries like Rwanda getting involved, especially as the UK looks outside Europe for its trading partners. They know it is the Queen's wish that Charles will follow her, and they have agreed to that.