Cape Cod-Orleans casual veg. frieldly
Hmmmm... just back from a week in Orleans. Not sure what there is in the way of ethnic or comfort food that is vegetarian-friendly other than french fries & onion rings at Liam's :) There used to be a place in Orleans Center featuring great middle eastern lunches (maybe the In Or Out Cafe?) but I'm not sure I saw it this year.
I would highly recommend Abba in Orleans as both ethnic and veg-friendly (and really, really good food), but your comments about fancy/snooty make me fear that you'll find it too high end (though our time there was anything but snooty).
As for tide pools, I think they are more a feature of a rockbound coast -- Gloucester/Rockport and points north have wonderful tide pools. You might find something like what you are looking for at the Cape Cod National Seashore headquarters in Eastham - there's a wonderful walk by the salt marsh out to the ocean.