Is re-sanding needed after primer is applied to wood cabinets?
should I RE-SAND all the cabinet doors again before I apply the final
coat?

I would. As cabinet doors they will be quite visible and I'm sure you want the best finish possible.  A light sanding after the primer ensures that the primer is smooth which will help you get a good finish coat.

Also...is there any tricks to making sure I get all the dust off
before I apply the final coat?

&quot;tack cloth&quot;