I like some of those combinations although I think something like shipwright and engineer would be very situational and expensive.

IMO something like an airship/boat should require all crafts and gathering classes. (kind of like a linkshell effort, everyone has to pitch in for the best results)

What with the addition of needing to learn recipes before being allowed to make items in 2.0, its a good chance for them to drop specialised recipes in instances and rare drops from leve chests etc.