Try
this build. It fixes the bugs you're complaining about. Those are just bugs, not a change in features. (Beta software is expected to have a few bugs, but beta 1 is closer to alpha in terms of suckiness.) That's why I posted this link earlier.
As for installing as a separate installation, that was because of how you instructed it when you ran the installer. It will create a brand new directory and a new installation if you tell it to create a new directory. If you change the default directory to a directory that already has a copy of Opera, then it will upgrade.