To disable flash, you can use the Preferences Toolbar extension -
http://extensionroom.mozdev.org/more-info/prefbar
I have not tried this with Firefox 0.9 yet (haven't been able to update for reasons not related to Firefox), but it's worked fine for me in the past.
I believe the other questions have already been answered.
EDIT: Oh, and as for HOW to set multiple homepages, I unfortunately can't tell you ATM, but I know you can. Unfortunately I'm on a crappy computer right now, using Mozilla 1.5 and the computer won't let me install anything else
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