I can answer #4 with a YES Any maemo app that can be run from the command line can be run in KDE. I've set up desktop shortcuts for all my favorite Maemo apps (eg: FBreader, SDict Viewer, ScummVM etc...) I know that XMMS, Kagu, Canola and Media Player all work as well.

If you want to set up a shortcut to the desktop: Open Konquerer -> /home/user/desktop -> Menu -> Edit -> Create New -> Link to application -> Tap on the icon to select an icon; give it a name - > Tap on the Application Tab and type in the Command that you used in Xterm to launch the application (eg: for XMMS it's simply xmms or for FOTAQ in scummVM it's usr/games/scummvm -f queen).

You can also set up a shortcut link to the system tray by doing a very similar set of steps: System tray menu -> panel menu ->Add Applet to Panel -> non-KDE application launcher -> fill in the blanks using the same method as above except here you type the xterm command in the Executable space. ** Be careful setting up shortcuts in the system tray though - deleting them is tricky because they all just show up as "Non-KDE" in the list of applets to delete. I accidently deleted my WiFi applet this way.**