Is it worth it to do the labyrinth on alt
Yes, you have a chance to get the exotics on any level.
Yes, I second that. I did it with my lvl12 Necro and the got the Med Armor Mad Slippers out of the FAMILY-SIZED
I got a pair of the medium slippers on my elementalist who was lvl 7 at the time. its worth it particularly if your server has no queue and you can get 3-4 characters into the chest befor it despawns.
I got the Mad King’s Britches on my level 38 alt.