Even the Ottomans didn't kill their Hospitaller prisoners and allowed them to relocate. Lascarids are trying to make peace with the Latins, not stir them up for no reason.
Åland being used like that against the Soviets likely ensures that Stalin demands it be given to his Finnish puppet state. And the Allies probably let him have it.
Crusaders would have trouble subduing the Islamic pastoral and nomadic peoples in Upper Egypt, but the areas around the Nile would be hard to separate from Lower Egypt and its cities.
Austrian keeping the Netherlands makes more sense in a scenario where the Rhineland is divided differently. Maybe give the Habsburgs Rhenish Franconia (Bavaria comes back to the coalition later, making them a target for territorial loss).
Venice is bottled in the Adriatic already limited in remaining resources and manpower. Candia can no longer be resupplied or reinforced. Venice should be seeking peace, but the Lascarids have no reason not to take everything now.
The Serb buffer doesn't have much time left, Alexandros and Murad will be land neighbors soon enough. Lascarids need to finish their wars with the Latins before war breaks out over Macedonia.
Venice without Dalmatia and Istria is in an awful strategic position in the Adriatic, especially with the Sicilians now firmly anchored on both sides. Venetian trade cannot be secured against a hostile Lascarid state and minor victories in the Aegean won't change that.
Alexandria is not really that far from the Norman center of power, I don't quite understand the talk of distances being too big. Egypt is a rich prize, far more appealing of a target than Tunisia which the Normans collected tribute from anyway.