Singa Crew, thank you for your reply.
About what to expect at your book launch... You know, I was just chatting with my favorite author (Christopher Moore who wrote 5 New York Times bestsellers and who's based in San Francisco), and he told me that his book launches are usually simple affairs between him and his fans. He said you pretty much have to be someone important and a New Yorker to have the sort of clout to throw a publication party.
So yeah, if a writer with 5 New York Times bestsellers under his belt thought that he didn't have the clout to throw a publication party, it is probably a good idea not to have one yourself.
If this is your first book, you are probably not important enough. So unless you are a New Yorker, the simple affair you are planning for your launch is good enough.