A few Opera related questions

I've been using Opera for ages, but there were always a few things I didn't like and just couldn't figure out how to change. Since I know a lot of people here use Opera, as god intended, I figured I might ask.

My first question is, how the hell do I disable Opera handling .torrent files differently from normal files? Opera being a .torrent client is something new, and I couldn't figure out how to disable that when I upgraded, even though I went through just about every single menu. That's pretty much the main reason I made this thread in the first place, the rest is mostly minor annoyances.

Second, how do I clear out the addresses stored in memory which appear when expending the address bar? I've never been able to figure it out on any version. Bonus points for a way that allows me to delete particular entries and not the whole thing.

Third question, is there any way to enable the old Opera behaviour for tabs? Namely, no "x" button, and left-clicking on the active tab brings you back to the last tab that was active before switching to the tab on which you clicked.

Fourth, is it possible to bring back the navigation buttons (back, reload, etc) to the main bar instead of where they are now, at the left of the address bar?

Jam it back in, in the dark.

Ok, the built-in torrent client is disabled. Thanks, I had never had to use the config page before so I never thought about looking there. As for clearing the addresses, pressing the clear button in the History section didn't work, as expected, since I tried it before.

The navigation button thing is ok too, thanks. Heh, that's weird, for as long as I've used Opera, I've always modified the default interface, but I never realized you could simply drag the buttons, even though I've often accidentally added new ones by dragging images or links over toolbars.

There's nowhere I can't reach.