No Need to Push
One of the most important things to understand about German Wheel is how to make it move. If you take a circle and put a weight on any part, that now heavy section will roll towards the floor. Now here is the magic of German Wheel; you are not just an idle weight but a living and more importantly a moving person. All tricks in German Wheel are based on this idea of moving the wheel by shifting your weight.
The second and subtler aspect of this is that an object has more pull the further from center it is. This is the same reason that holding a 10 pound weight with your arm straight out is much harder than holding it to your chest. This means if you want to go faster you need to move your body further from the center of the wheel, and if you want less speed you stay closer to the center of the wheel. This principal applies to every aspect of the wheel.
When many beginners try to add speed into the wheel they “push it”, which can add some power into the wheel but it has two distinctly negative effects. Firstly, it makes your movements appear more effortful. Makes you look like you are working, which is fine if that is your intended aesthetic, but unless you are going for that clunky effortful look I would recommend avoiding all unnecessary strain. Secondly, it is less efficient; many times I see a student pushing the wheel so hard that they are pushing their own body weight backwards (in the opposite direction from where the wheel is traveling) and actually slowing the wheel down more than they are adding power into it.
Go back to those safe basic tricks you know and mess with them. How does bending your legs, or catching a different place change the way the wheel rolls. The more you understand about how to move the wheel the more control you will have and the more effortless your wheeling can become.