Just bstarted that today. Built two cages on Isle of Siptah PVE Server 2130 on Xbox and currently have a level zero Daicas The Sharp and a level ten Vais The Wayfaerer for sale. Two named volcano fighters that I hired from a tavern.
You may be able to sell and buy Bazaar and Battlepass stuff, but the buyer may not be able to use them depending on how how they get them…
If a Battlepass/Bazaar armor/weapon already is equipped on the thrall, they might be able to use the thrall as it is, but the second they remove any piece they don’t own themselves they cannot equip it on them again.
As for Battlepass/Bazaar mounts, I’m pretty sure they won’t be able to ride them unless they own the right to make them, my clan mate and I tested this a while ago, he cannot ride my Wight horse since he doesn’t own the battlepass it came with, and I couldn’t re-equip a Bazaar armor he put on one of our thralls, also if he placed a Bazaar item, I could move it from place to another, but if I picked it up then I could not place it back again.
There are lots of things you cannot do with Battlepass/Bazaar items unless you own them yourself, however DLC items have always been able to be used by players not owning them as long they weren’t items that only can be placed using the building hammer
Yes as long as nothing is removed from the thralls items should stay. Mounts were given an update a couple of months ago for people on same clan to ride while not owning item from bazaar.