Several suggestions... first, you can skip through the tabs very quickly using hotkeys. If you hit the ALT key, you'll see letters and numbers pop up amongst the ribbon commands. Press the corresponding letter or number to access tabs and commands without having to use the mouse. This can be very, very fast.
Second... you CAN customize the ribbons in Creo 1.0 (Creo Parametric). Right-click your mouse in the ribbon area and select Customize the Ribbon. There are more options and possibilities than I can cover in a single post. Try out the different options. You could make your own custom tab with all of the commands you want positioned underneath it.
Finally... use the Quick Access Toolbar. You can use the little "^" up caret arrow to the right of the ribbon to collapse the ribbon toolbar. This will leave only the smaller, floating Quick Access Toolbar. You could try adding most of your commonly used commands to this toolbar (right -click and select Customize Quick Access Toolbar). You'll likely not have room for everything you need but by utilizing a combination of a customized ribbon, a customized Quick Access Toolbar, and the ALT hotkeys, you can work very quickly in Creo 1.0