If possible, only extrusion features and no rotation features should be used. See Section 3.5.3, “Regular Bodies for VDI Models”
Absolutely avoid cut of edges (single edges may not touch each other):
It is not allowed to subtract volumes more than 1 time (cut features should not touch each other).
In the case of planar faces interpenetrating solids have to be avoided.
If interpenetration is constructionally needed, then pay attention that you have solids (not hollow bodies) and that the interpenetrating solids do not break tolerance limitations.
For a connection between a round body and a rectangular body, it is best to place the rectangular body at the center of the round body.