You make some good points. No. 1 on your list is already available (if I understand you correctly). It's certainly not as intuitive as it could be, but I have near-instant email notifications about new threads / posts to threads in whatever "spaces" (sub-forums) I have subscribed to by clicking the "Follow" link near the top-right of the screen. The missing link for me was that I had to turn all the options to on/yes in the "Welcome Carniphage" > Preferences link at the top-left of the screen.
As a workaround for no. 3 (there shouldn't have to be a workaround of course), I select my entire post with cmd+A and then copy-paste it with cmd+C , V before submitting it as that regularises all the text. The whispered text occurs when you delete a new-line to bring text into the paragraph/line above if that helps anyone trying to diagnose the issue (and the rest of us avoid it until it's fixed).
Clearly the designers of the site don't use iPads either. Trying to edit posts from an iPad is such a horrible frustrating experience I tend to stay away from the forums when away from the computer. The auto correct / capitalization is completely broken.
Apple is just a user, here, same as us, albeit with elevated permissions.
Complaints should go to JIVE Software, Portland, OR. This is actually their stone age linux package (w/windows roots), but clearly Apple went with the lowest bid. In any case, I'd not hold my breath for things to change.