Those are good tips.  If you go with the airtight container, just make sure there is no moisture in there before sealing it.

For softgoods like waterproof/breathable pants and jacket they make special wash to care for that.  An example is Nikwax TX Direct.

For snowboard, I never do the thick coat of wax deal.  I guess if the only place you have to store your ride in like in a garage or something, then yeah, do that for sure.  I keep my boards in my house only always.  Storing a snowboard inside for the summer ensures that temperature and humidity levels are controlled which helps preserve the base and edges.  Simply put the board will last longer and you will spend less in tuning / repair fees.