Yup, the sun rising in the west and setting in the east is almost certainly Quentyn. The seas going dry is what's happening to the Dothraki Sea (presumably due to the oncoming great winter). Mountains blowing in the wind is likely a reference to the pyramids burning, but it's also possibly a reference to Gregorstein: if he is defeated or destroyed in the trial of battle, it could refer to that (and timeline wise it might be concurrent with Dany's trip to the Dothraki sea).

For Quaithe's prophecy, the pale mare is the disease. 'After her come the others' could be a reference to the Others, or simply to the other parts of the prophecy. The kraken is Victarion, the lion is Tyrion, the mummer's dragon (Varys' dragon) is Aegon and the griffin is Jon Connington. Although neither Aegon nor Connington came to Meereen. The sun's son is Quentyn.

The perfumed seneschal is the ship bearing Moqorro and Tyrion to Slaver's Bay: its name translates as 'fragrant servant'. The other possibility (Dany's servant) seems rather over-obvious. Unless GRRM wants us to think that and the ship is a red herring

The 'dark flame' is likely Marwyn; he is (possibly) bearing a Valyrian candle (an obsidian - dark- flame) with him so he can stay in touch with Oldtown. More to the point, GRRM changed this chapter in edits from an earlier draft that much more explicitly pointed to Marwyn. However, there is also a theory that it's a reference to Moqorro (a dark-aspected follower of R'hllor, the flame). This may depend on if the ship theory is right; if it is, there's no reason to refer to Moqorro twice.