The team has done much to accommodate our wishes, so thank you very much, K-Team! I've therefore removed my many redundant observations and provided a consolitaded request here in the OP, which I'll keep updated.
Note to all
If, like me, you issue "Likes" to all who post on your wall, check that they're still-there. All likes, both given and received, disappeared from my wall with the software upgrade and whilst I can't give them back to myself (obviously), I've re-liked every visitor's post.
Also check your Conversations area and be prepared to delete a bunch of old ones that you might previously have left. I went from a few pages (maybe 20% full) to 101% due to all the legacy PM's that reappeared. Nobody could PM me at that point, so have a look and remove whatever's redundant or necessary to free up room.
Lastly, make sure you haven't lost your notifications preferences. I've been wondering for some time why I haven't been notified about new followers and other things since the update (it's New Year's Day now!). Turns out 3 of my preferences were toggled the wrong way.
Consolidated requests:
Wall
Add ability to add attachments.
Add ability to use emojis in the same manner as the forum.
Restore the customisable-background feature.
Restore the ability to edit posts.
Restore the "Recent Visitors" display.
Conversations
Add ability to add attachments.
Restore the ability to edit posts.
Members link
Please bring it back.
Forum Panes
Restore the Recent Activity window. There's enough room below the "Latest Posts" pane to add it 5 times over; why not use the dead space?
Bottom-of-page forum stats
Who is the newest member?
How many members are there?
How many and who is logged in?
How many joined the forum in the last 24 hours?
It's the standard M.O. for forums to provide this sort of information.