What IP or userbase does Opera have that either Google or Apple would want? If either of the two of them wanted to copy Opera's browser features they would just go ahead and do so.
If anything this makes Opera less interesting as a potential purchase. Their rendering engine was a massive piece of original IP.
They mostly do. Dozens and dozens and features. But it works other way around as well, and it's a great thing in the end. The most beneficial features are virtually on every browser.
How can it be worth anything when the competition is free?
Do you remember how long it took Google to port Chrome to Android? There was a Firefox and Opera release for Android even before Google got their own browser ported to their own OS.
That's why I installed opera on my phone. It works so good, I never bothered to install chrome on it. So it looks like I'm an Opera user. Granted I still use chrome/FF on everything else...