Are you allowed to bring small hand held fans to the Mann?

Yup

Yes

I would think so

Worst parking lot ever.

Not sure but can't imagine it would be a big deal. Maybe call?

I saw some people on the 19th with some fans

They didnt hand out any at Harry's concert and it was quite warm.

I don't think you can bring them in, you would need to buy there.

Yes. They actually gave them out at the concert I went to.