I was wondering the same about removing Qt 4.5 files.

In my experience (now that I went through this last weekend) all those instructions can be reduced to:

- Get a recent Ubuntu.
- Install the full Maemo 5 SDK via GUI installer.
- Install the libqt4-maemo5 libraries to get Qt 4.6

Enjoy!

Back to the original topic, I recommend you top ask in the official support channel: http://qt.nokia.com/developer/qt-for-maemo-developers ("How to provide feedback"). Not only because there you ave the Qt 4.6 for maemo experts, but also because this way they realize easily the libraries are used by more developers, they put more attention to fixes and new releases, etc.