Custom toolbars that do not offer the options, will get you part of the way
there. This will not disable the keyboard shortcuts, but will make it
harder for the person stealing your presentation.
What version of PowerPoint are you using? There are better options,
depending on your version.
Maybe you can describe why you would want to do this and we can then offer
some alternatives. Are you trying to protect your presentation? What
version of PowerPoint are you using?