Actually back in Opera 5 or 6 or thereabouts I could set Opera to open in new tab only when I said so myself no matter what the html said, so 12 is less good than older versions, but still a lot better than 24.

Actually, you could do that in 12, in opera:config

4 The ability to ctrl-tab in most recently used order. It's the only reasonable way to do it, but now no browser does it that way. Alt-tab still works in most recently used order.

opera://flags/#activation-order-tab-cycling

That's pretty well hidden.

5 F2 for mouse-free entering of URL. It's not as big as the others, but I still miss it.

Don't know if it's what you want but F8 selects the address.

Yes, that's a good alternative. Thank you.

So far I'm missing:

1 F12 quick settings; absolutely essential for quickly turning java/flash/animations on or off.

2 The ability to turn animations off. A lot of sites are unreadable with animated ads and other content jumping around.

3 Open in same tab on right click menu. I hate web developers who want to open everything in a new tab/window, and now I no longer have any choice. Actually back in Opera 5 or 6 or thereabouts I could set Opera to open in new tab only when I said so myself no matter what the html said, so 12 is less good than older versions, but still a lot better than 24.

4 The ability to ctrl-tab in most recently used order. It's the only reasonable way to do it, but now no browser does it that way. Alt-tab still works in most recently used order. Mostly I have 2-3 tabs that I use all the time and several that I use every now and then. I guess the natural thing to do would be to have a single tab for the rarely used sites and use bookmarks, but thats more work and now those seem to be lacking too...

5 F2 for mouse-free entering of URL. It's not as big as the others, but I still miss it.

I guess an adblocker would to a large extent mitigate the problems of 1 and 2, but why force people to the extra hassle?

What's better in 24 than 12? Haven't found anything so far, so switching back now. The 12.17 download was well hidden, though.

Why do Opera keep removing all the features that made it better than the others? I've been using F12 daily, although it did get less useful when I couldn't toggle java and flash separately anymore. How am I now supposed to toggle addons on for sites that need it and off for sites where it's a nuisance?

Only things left is one-key shortcuts. If they go, or Firefox starts implementing them, I'll switch in a moment.