It may be the only way to find some of thing things preserved via citizen archives. I enjoyed the talk Ian MacKaye gave there about archiving the live performances of Minor Threat & Fugazi. Here [1] is a post on the subject.
Hmm, that seems unlikely but I honestly don’t know. Possibly free for US citizens but a small fee for visitors? I can’t imagine it would be closed to visitors, though you should be able to contact them to find out.