I would like to see some of it, but do not want to spend all day there like my husband. Can I come and go out then return to pick him up?

Yes it is tiny. You can easily buzz through the things you want in one hour. Three hours to study every inch of the place.

Is maybe 2 Hr. Is not too much

You can see everything in less than 3 hrs

Yes

Yes, and honestly it is not that large of an exhibit. It is not an all day, nor half of a day exhibit. Maybe, 2 hours ... add more if you do the activities

Yes...there is also a sandwich shop inside for a quick bite to eat!

Yes you can