Is the light/fan combo in my shower safe?
For the record, I have never liked lights (or fans) in the shower, because they are a maintenance nightmare. That being said I know of no restriction about putting one in a shower area unless you are able to touch it or it comes into contact with the spray of the shower. So I am assuming your fixture/fan is high enough to meet all jurisdictional codes. 

My only question would be if this was installed during construction or was an add in by a previous owner. If it's the latter, you may want to check with local code enforcement to see if it should be removed. I like your idea of never using it.

Stay safe.