A question - although it doesn't have many stops on the Bournemouth-Ringwood section (because it is running on fast main roads), does it actually pass any stops that it could stop at, but doesn't? This I think would be the definition of a 'limited stop' service.
From what I can make out, the X6 indeed doesn't actually 'skip' any stops - it's just a case of the A338 doesn't have bus stops along it. I don't believe the lay-by stop (one for each direction) half way along Queens Park, between the town and hospital, have been in use for some years? So given the X6 observes all stops along its route, I'd suggest 'normal stopping' is indeed the correct categorisation for it?
One could therefore also argue that the 3x should also be 'normal stopping' too? I can't see any bus stops that it skips either, with the 'x' suffix just being to differentiate it from the slower 3, which runs through residential areas rather than the 3x's route up the A338.