Hello,
I appreciate your hard working to make this game ongoing. First of all I still didn't fully explore the whole game, so my suggestion is based on my knowledge. Since farming has become easier and longer, I found teleportation to NPC's is pretty useful pet skill. So, I suggest if it possible to add a new skill that respawn a good merchant for 5 minutes duration using Pet's. This would be cool for isolated farming spots.
I have the skill to sell items but is pretty inefficient.