Question: If null void is cast over a bunker will units inside be able to cast spells? Question: Since repair is technically an ability, can it be cast from inside bunker, i.e. repair it from within? I think it is implied you can't but I just want to check to make sure (Hopefully not). Question: Can a medic heal a unit within the bunker? For example, inside your bunker you have 3 marines, 1 medic and you stim the marines. Do they get healed by the medic?

The Null Void ability currently prevent units inside bunkers from casting. Repairs can only happen from outside of the bunker. Medics inside bunkers will be able to heal units inside a bunker, but Medics outside of a bunker will not be able to heal units inside a bunker.

I'm still not sure about the null void stoping abilities that don't cost energy (blink, overload, repair, build interceptor) but 3 answers from the man himself is great.

Null Void only stops abilities that costs energy, which does not include abilities mentioned above, such as Blink, Overload, Repair, and Build Interceptor. On the other hand, Null Void will act as a detector, allowing cloaked units to be seen in its area of effect.

Question: But medics in a bunker can heal units outside a bunker?

Yep!

Question: You said in a recent post that units can only attack with one weapon. So what's happened to the Viking's transformation technique? In the video they attacked air w/missiles and ground w/machine guns. Has that been changed?

Yup, in ground mode, the Viking will have a different weapon than when it is in air mode. The Viking is also undergoing balance changes in which while in ground mode, may not be able to shoot both air and ground units. Of course, we're still far from finished in terms of balance, so much will still change.