Hi Tombas - glad to hear it's going well.
To answer your questions:
1) I may add a velocity clamp in future. Before then, you can obtain the VelocityX and VelocityY of the body you wish to speed clamp from the expressions.
Then get the angle of travel, using VelAngle = angle(0, 0, VelocityY, VelocityX).
Then get the absolute velocity using VelocityAbs = distance(0, 0, VelocityX, VelocityY).
Let's say your clamped max velocity is MaxVelocity, then the final velocity will be VelocityFinal = clamp(VelocityAbs, 0, MaxVelocity).
To apply this to the body then use action Velocity at angle to set the velocity to VelocityFinal at angle VelAngle.
I may add this in future but I'm working on something else in the plugin at the moment. Hope this makes sense?
2) You have all the correct settings there. Other tips would be standard for C2/C3 - minimise jank by avoiding creating/destroying large numbers of objects at any one time, etc.