Unfortunately, I don't speak Mandarin. If I did, I would've posted a question there already. ^_^ I wish I did, though. I wish I spoke German, too, for that matter. Apart from the Anglosphere, these two language communities seem to produce more developers than other communities.
Not only did your second suggestion provide solutions for 2. and 3., it effectively ended up producing one for 1., too.
The help message for the switch --tray says it causes the main window to "minimize to system tray", which turned out to be wrong. And this is a blessing in disguise for me.
I tried
bitcomet --tray
and found that it actually brought it out of the tray!
Thanks a ton, Guardian Eagle. :D
p.s. 1. For anyone interested, to send the BitComet window to the tray, I've set the "Main window placement:" option to "Minimize to system tray" and either press Alt + F4 or another hotkey that I've set up to activate the following AutoHotkey command:
PostMessage, 0x112, 0xF060,,, A ; 0x112 = WM_SYSCOMMAND, 0xF060 = SC_CLOSE
p.s. 2. Maybe it'd help other users to update the help message and the wiki page to reflect the above finding. Other parts of them seem to be outdated or incomplete as well.