I want to keep the Unity launcher only and remove the panel. Is there a way to do that?
Not a complete answer, but you'll need to disable Global Menu first :
sudo -s echo "export UBUNTU_MENUPROXY=" > /etc/X11/Xsession.d/81ubuntumenuproxy
Then restart your computer. If you want the Global Menus restored, simply remove that file (
sudo rm /etc/X11/Xsession.d/81ubuntumenuproxy).
After that, if you can delete the top panel somehow, at least you'll keep most of your functionality. You'll need some kind of replacement for some of the indicators, like network-manager and the session menu.
Use gnome to run the unity launcher (with it you can completely remove panels, since unity uses nautilus anyway it is essentially the same), and then run
unity-2d-shell to get back just the unity launcher, you can then add it to start-up programs, by running
With this you can even run the unity launcher in xubuntu! And it solves the window maximizing bug where the close icons disappear or move to the other side.