I was thinking about the Terranite Cave a lot lately... I would like to propose a possible update as far as the monsters found there. Being a cave, I think that the spiders should stay. I also think that scorpions and/or snakes could/should be added. I would also like to see either more overall Terranites, or a faster respawn rate for them in the cave. And to add a little more balance, the Skeletons and Lady Skeletons can be removed.
I don't think the map itself needs updating, but I do think that the Terrante respawn rate or total number of Terrantes and Terranite spawning spots in the cave would be fairly fitting.