Is it possible, without the use of any other cards, to move an attachment from one hero to another? IE - weapons or things of that nature?

You would think that if you were traveling along in a party with other people, they would be able to use each others weapons.

No, not unless the attachment specifically allows you to move it from one character to another. For instance, all of the Dunedain attachments have Action: abilities that allow a player to transfer them between heroes. In general, though, attachments can't move around.