Comprehensive archives of past discussions are available from Listserv back to January 1990 inclusive. You'll be removed from the list.
First choice is the default.
Only one of each option is allowed. There are exhaustive lists of DOs and DON'Ts available elsewhere, but for the most part they are all just common courtesy. Likewise, responding to 'flames' usually merely incite more, and are a waste of the networks' bandwidth. Generally, short ads posted infrequently are tolerated on the list. A URL in the listing pointing to more detailed information is also preferable.