Is this the spell that offers bash protection?

I've only recently started messing around playing mages and am trying to figure out where the bash protection comes from. I know its not wands. AP's don't get bash protection. Necro's get wraithform. Since wraithform operates similarily to pass door, is it pass door, which I'm pretty sure is the translucent flag, that also provides bash protection?

Yes, wraithform is both bash protection and pass door

Necromancer: Wraithform (at level 36)
Transmuter: Passdoor + control translucence
Shapeshifter: Passdoor + control translucence
Invokers: Major shields
Conjurer: No spell to cast, but archons/devils give protective shield

Shaman: Protective shield

It does not. Controlled translucence I think it is (shifters and transmuters I think get this spell, which might be advanced pass door) and greater shields (invokers) are usually what is used for mages' bash protection if I'm not mistaken. Regular pass door I am sure does not give it though. Shamans and healers get some form as well, armor of thorns I think for druid.

Hope that helps a little.

Pass door lets you walk through most doors, but doesn't help versus bash/throw/etc. It's a common prep because of this.

The ones that do protect from these are either controlled translucence as stated above, some invoker shields, wraithform for necromancers, protective shield for shaman/healer, and armor of thorns for druid. Protective shield and the invoker shield only helps against bash, while the rest also "include" the effect of pass door in some way. There is probably a few I'm missing, but it's not a common prep and usually comes from a class ability.

If you're having problems being bashed and you don't have one of those options, try getting enlarged to be bigger than your opponent or reduced enough so he cannot bash you in the first place.

Hope this helps.