I'd like to change the icons and categories that appear in KDE 4.4's Search and Launch. I don't need to see Education, Games, Contacts or the bookmarks, and I find them rather annoying; also, the System and Utilities buttons are very small. How can I do this? My previous attempts culminated in disaster.

To get rid of "Education", "Games", "Bookmarks" and "contacts" right click on the desktop, go to "Configure Search and Launch" and click he "Main Menu" button/tab on the left. The resulting window should allow you to uncheck the categories of programs you have no interest in seeing.

Can't help you with changing the button sizes though.