Is Hex worth it at high levels?

[Witty Username]

But 1 and 2 also rely on the "unintuitive behaviour" of killing a squirrel in the morning.

Not nessasarily, usually how this comes up for my group is hexing for a early combat in the day, and then it happens to persist, which isn't all that unintuitive.

3 kinda does, since it is predicated on non-combat and so would nessitate forcing a hex senario to get the full effect of unless your day happens to match up with what you need.