If a user has Copy+ 2014.x installed on multiple machines, are the dongles (and the clicks) hot swappable?
Are Clicks associated with the dongle, or the machine?

The clicks are on the dongle, the dongles can be moved around on machines, assuming the licenses are setup correctly. For safety you may have to shut down copy+ when you change the dongle and restart. You cannot swap dongles between 6.x and 2014. Dongles are only compatible with the version they would set for, i.e. 6.x dongles only work with 6.x and lower, 2013 and higher, e.g. 2014 only work with 2013 and higher e.g. 2014