> What are the disadvantages of using Events?

You cannot carry dynamic data with them.

> Is there a limit on the number of events that can be used?

Not aware of any limits. I would use them sparingly.

I make message queue tables and simply use events to do a wakeup to process
"messages" from the queue.

FWIW,
Jason Wharton
CPS - Mesa AZ
http://www.ibobjects.com