re. 1) yes you'll have to to mute/solo the tracks you want mixed-down and exported to file, sorry for not mentioning that before.
re. 2) you have to select one, more or all clips in a track, that should be the current one anyway (Ctrl+T), not quite selecting all and everything (Ctrl+A).
iow. there is no such a magic spell or command for you to export each track into a file in one go, sorry again.
re. 1) yes you'll have to to mute/solo the tracks you want mixed-down and exported to file, sorry for not mentioning that before.
re. 2) you have to select one, more or all clips in a track, that should be the current one anyway (Ctrl+T), not quite selecting all and everything (Ctrl+A).
iow. there is no such a magic spell or command for you to export each track into a file in one go, sorry again.
byee