FourWheels, all the crucial information is summarized in the first three posts (or, at least, linked to in one of them). It makes finding what you need to know a lot easier.
Absolutely nothing is mandatory. You can attend just the dinner, or join us just for drinks on Friday night, or even go only on the shopping (although I believe that the last will be the most lightly attended).
You are also free to schedule other group activities. The only two restrictions:
1. They can not conflict with the dinner or Friday night drinks.
2. If announced here, they have to be open to all those attending.
I do, however, ask that if someone is not going to attend either the dinner or Friday night drinks, that he let me know in advance -- simply to let us have a good idea of how many will be there.
I'll keep you on the "possible" list until you tell me that you can be moved up to "definite" (or taken off the list completely).