I would absolutely expect a refund for any obsolete/changed guild marks actions/traits that have already been purchased.

I would love to be able to use guild marks for things other than actions/traits. I would love to see vanity gear for each class, useful gear with stats for each class that is very class specific, items to use that are consumable to help players in that class (how about anima scrolls, free airship passes, buff scrolls, etc), and also items for display (with beneficial stats) for the new player housing.

I liked the concept of the specializations in the crafts - however, many crafters ended up with all of them anyway (and in multiple classes). There wasn't much of a uniqueness gained by purchasing those specialties. Also, having those specializations didn't really seem very noticeable. If they choose to continue something like this in the future, then choices would need to be limited (say a couple of them per class, and unique to that class) and also make the difference really have an impact on that type of synth.