Goblin camp is probably THE location in which fast travel doesn't work for me. I just feel we shouldn't be able to teleport away while deep in enemy territory after taking down their leaders.
An option I often use is to decent directly to the underdark, though I haven't found a handy way back up yet, without using the fast travel system.
While we are all perfectly entitled to play the game however we wish, I personally don’t find sneaking out of the camp cheesy (in response to Domoslaf’s point), but only fast travel when there’s a clear path to the nearest portal (my head canon is that the portals let you jump from one portal to another, but not from just anywhere to a portal). So I would only use a portal to escape the goblin camp if I’d either cleared the way to the portal in the Underdark temple, or to the one outside in the camp, from which I’m happy to jump to any other portal. That said, given that I think there should indeed be a delay between killing Ragzlin and the whole camp turning hostile, I could convince myself that what was “actually” happening if I just fast travelled from Ragzlin’s room was that I was escaping the camp before the goblins noticed what had happened.
As to routes back from the Underdark that don’t require fast travel at all, I agree those could be improved and think there should be ways to sneak into locations from below. I think, if you’ve not dealt with Ethel yet, you can use one of the fairy rings down there to jump to the one outside her back door. But if you have then it takes you to her lair behind a magic door (I assume you can get into her main lair then out this way if you use the masks, but have never tried that as it’s a faff). But Zhent’s elevator is locked from the top, isn’t it? And the jump from the spider lair is one way (even if you can fly).
Gah! And I said I’d stop taking us further off topic. Definitely stopping now … at least for this subject .
"You may call it 'nonsense' if you like, but I've heard nonsense, compared with which that would be as sensible as a dictionary!"