Right click and chose close tab. You can usually go to File and chose the proper action as well. Ctrl + T makes a new tab and ctrl + W will close the active tab.
You should be able to right click on the Desktop and create a link to the opera app. On some you can drag it to the panel as well.
Hope that helps.
Acutally, if memory serves me well, you can go to start thingy then Configuration then Other then MenuDrake. When that comes up, it may take a bit, select menustyle and the put a dot next to All Applications and then click OK and then the save button. That will usually add those missing apps. There is a command line one to. Anybody remember that thing? I think it is menuupdate -v. Not 100% sure.