Please publish to the snap post category for issues regarding a particular snap, I’ve fixed for you.
Yes.
No idea what that is, however, there’s a problem that development resources(even if available) will be on a different path and you may need to change your build configuration to reference it.
Contact the publisher to be sure.
It depends whether the developer has distributed different versions of the distribution via Using Tracks or other means(like different snap names for different versions).