Are decisions taken at the Meetings of the WCC binding on the Member organisations?
Any agreement reached at these meetings is only valid if it is ratified by the Member organisations. If it is ratified, then it is the Member organisation which implements the relevant action.
If I want to bring an item to the WCC, how do I go about this?
You should contact the Executive of your own organisation by whatever route is normal within that organisation. An individual cannot put an item on the Agenda, only a Member organisation.
Can anybody attend the open meetings of the WCC or is a ticket or invitation required?
The open meetings are exactly that and any individual is welcome to attend and take part in the meeting. However, they are often in conjunction with a Seminar and sometimes a charge is made.