just because the mags are switched off, definitely doesn't mean that they aren't live. A bad earth is all that's needed and you have a live mag, it's one of the reasons you do the mag check
.
Always treat the prop like it's going to pop on you but running your hand down it wont cause a problem, it's only going to threaten injury when you pull it past the "click" which is something one would do with a strongarm starter
. I can't see a good reason to look at the prop either way what you're looking for is evidence of corrosion or a chunk missing you should be able to see or feel it.