Joint Base Cape Cod

Yes

Yes there is.

If he is in the car with you, you can get on base. You cannot use his card without him present.

Dont no

Your best option is to contact the Public Affairs office of one of the Military services that operate on Joint Base Cape Cod (JBCC). That would be the Massachusetts National Guard (Army and Air Force) or United States Coast Guard. They may be able to arrange a tour. I also suggest keeping an eye out for any Open Houses or events hosted by JBCC that are open to the general public. Good luck, Peter. Hope this helps.