I did Docks (A). I must say I think there were lots of overestimations about its power. Yes, it can be powerful sometimes, especially with Fishing Village, but in other cases, is hard to make it work. Once you have an engine, you can add a couple to provide stability, but it does not make an engine on its own and it is AWFUL for Big Money, much worse than Smitty and nothing compared to Wharf. Especially, its pretty hard to find a good moment to add it, unless you have a gainer, when it really shines.
Also, Docks (A) only provides +Cards, so even when it shines, it will "only" draw your deck. And it will do it with much more difficulty than Scrying Pool, for instance, that also attacks and is non-terminal.
It is not too good as an opener (too slow), does not provide money or Buys, but it has potential in some engines without trashing, and I like those cards: sometimes really powerful, but not the majority of the time.
I will just end my vent with this: I loved that WW thinks its probably weak in the video and several other people think its incredibly overpowered. This at least left me thinking it was interesting to analyze.
Anyway, I like the two cards that got to the seaside finals, but I think we are kind of pointing too much to complicated cards for an early expansion like Seaside. Complicated cards are always more fun, but I feel like a true Treasure Chest should respect more or less its origin, and have complicated cards in the later sets only, like the original expansions.