Correct me if I'm wrong but didn't Throne of Bhaal go even above level 30?
You're right. Characters could have reached level 40, if my memory serves me. In any case, this level is even higher than that of Elminster. But the original series was based on the second edition.
I think I've read cap would be 10 but they might raise it because they've already have so much content prepared
Yeah, I would like the level cap to reach at least level 12.
still quite a lot for goblin
Well, in my memory, two adventures in the fifth edition provide a background for many 5ed race, including the goblins. And each of them is designed for levels 5-10.
