I have a lot of the same problems you are describing but my biggest problem is text messages. Mine too deletes them all randomly. And I figured out that it sends old texts from your "undelivered" box. Whenever a message fails to be delivered it gets saved there, then when you restart your phone, it sends them all. Now before I restart I always make sure I don't have any undelivered messages. Otherwise it is just asking for trouble from people lol.
I also have a problem with phone being super slow to keep up with typing and seeming to freeze after every letter you type. Swype seems useless when it happens.
it's not the best phone, but I wouldn't say it's worst. Worst android might be motorola cliq.