Spirit Island questions

Hi, I'd need a few clarifications regarding rules.

• Pushing colonists: ever since we tried the Ocean's hungry grasp spirit, we really like to play with push and pull cards to optimize our other, destructive forces, and we've been pushing stuff from shore areas to the ocean to instantly destroy them. Rereading the rulebook (after like 15 plays) just for the sake of it I came across a line that forbids pushing stuff into the ocean. So... we've been wrong all this time, and only this spirit can push / pull stuff to the water?
• Blight. We find it brutally and overly punishing that it removes presence tokens of spirits. So we came up with a houserule that multiple blights can be placed on a single area, this way the island can still get so polluted it is irreversable, but we won't be tied up and paralized fighting against the colonists. Is there a more commonly accepted, perhaps better balanced way of dealing with this issue?
• How are we supposed to play the nightmare spirit? I get it, fear generation like no tomorrow but without some built in mechanic to remove blight (and perhaps feed on it which would be very thematic) it's just... pointless to have this spirit in the game at all, there is no way to win EXCEPT with getting all the fear cards, since you are pretty guaranteed not achieving 0 cities+villages or just 0 cities, when one player's part of the island is just... never really kept in line, until later when other player(s?) can afford moving over there a bit with their presence, at which point there are likely a half dozen cities there at the very least.