I'm pretty sure we've got this right, and also pretty sure that it's somewhere on the forums already, but I'm just not seeing it. Sorry. :-P
If an investigator is in an Other World and gets an encounter that tells him to "Return to Arkham," but there is no gate leading to that Other World at present, is he Lost in Time and Space just as if he moved to the end of the Other World normally?
This came up in the most recent game. Investigator 1 (I1) had an Elder Sign, the other (I2) had an explored token. I1 moved to the I2 and gave him the sign. However, I1's Arkham Encounter came first, so he was sucked through the gate (he hadn't had enough move to get back off the gate after trading). I2 used the Elder Sign to seal the gate, and I1 was left without a way back. (Heroic sacrifice!)
On his second turn in the gate, he got an encounter that said to "Return to Arkham" if he succeeded. (He failed, so it didn't end up mattering in that game, but the question still came up.) If he had succeeded, would he have been LiTaS, or would that have given him a way out?
Second question: We were playing against Yibb, and multiple times when we had 5 clue tokens already, we got encounters that would give us clue tokens. Do those tokens vanish, or are they placed on the board at that location for later retrieval? (We played that they just vanish.)