Event Handling System

I have the following questions regarding the Event Handling System:

1) What events can be triggered and what do they do?

2) In what order are the 'top level' events triggered? For example, I know
that there are 'ServerRequest' and 'OnSessionCreate' events - I would assume
that ServerRequest events happen before OnSessionCreate events.

3) For a particular event eg. OnSessionCreate, in what order are
OnSessionCreate events triggered. For example, I have module foo and module
bar, both with OnSessionCreate events. Is foo triggered before bar, or bar
before foo?
- Is there any mechanism to influence this ordering?

4) I know that when a OnSessionCreate event is triggered it will happen
before part/all(?) of the Xaraya API is loaded. For example, I know that
XarModAPIFunc is not available at that point. What part of the Xaraya API is
available?

Cheers for any answers.