#1 dynamic 3d sketch: I am not aware of such function in Alibre Design
. The workspace won't update until the designer exits out of the sketch mode. Any changes made to the part will then show once the sketch is completed and sketch mode is exited.
#2 Orienting two parts in relationship to each other. This is an assembly function in Alibre. Basically, Alibre offers two different work flow types for defining 3d mechanical part assemblies: "quick" constraint mode and "explicit" mode.
In a sentence, to use Alibre Quick Constraint mode for defining assembly relationships, Press CTRL-Q and select the face of the first part of the relationship. The selected surface should turn green indicating its selection. "drag and drop" the part (holding down the mouse button) along the second part surface and select it (by releasing the mouse button). An option box will appear for defining the type of relationship defined (i.e. parallel tangent etc)
Alibre offers users a free tutorial training video on how to apply assembly constraints here:
Maybe have a look at these?