That antlion pit sounds interesting. And not because it might tickle the fancy of one of my fetishes. But I do agree with you for the time limits. They never fail to stress me out, and in certain situations, I have a hard time enjoying the game when rushed. Perhaps instead of a time limit, there could be a sort of "choice limit". Like trying to solve a puzzle to get out of a trap, but every wrong answer brings your game over fate closer and closer.
As for what else to see in an Egyptian themed area...hmm. You already have a few of the common ones, like mummies and sarcophagus. I guess maybe quicksand would fit in? Or perhaps if you want to have more puzzle elements, maybe a Sphinx enemy/obstacle. They could be blocking the way forward, or maybe a secret area with some useful items. You'll have to answer their questions correctly to proceed, but if you get their questions wrong, they'll swallow your party whole. There could be noticeable details throughout the tomb area that the questions could be about. Or maybe questions about other enemies, so that you're more encouraged to fight and learn about them. Or instead of getting one question wrong and you're done, you could have three chances. One for each party member. And for each one wrong, you'll lose a member to the Sphinx. And you can try to get them back by getting other questions right.
Ah, I'm rambling with ideas again. Sorry about that.