I'll answer Susan's question first. You don't need O2 for the head of the matches to ingnight or burn. The compounds involved have their own oxidizer so they flare. Only when it comes to the stick part does it need an outside sorce of air.

Buckey has it right glue the striker strip to the inside of the cap so it staysand is available for use. Then put the matches head end down. If the tips are at the other end they can't touch the striker strip.

If you use strik anywhere matches almost any surface rough dry surface will work. But in wet weather anything outside a sealed unit just might be damp. This would ruin the chances and the match.

If you use safety matches you have to use the box striker strip as it has half the chemical compound that makes them ignite.

I know that dipping a match in paraffin will water proof matches. I have also heard but have personally tried Thompsons Waterseal works well. This wouls not significantly increase the match sizes as the paraffin will. I do know that over time the paraffin will degrade the matches. I haven't heard the long term effects of the Thompsons. But because matches are such a necessity they should be checked regularly. If there is any sign of degridation the need to be replaced.If either method is used you must coat the entire match not just the head. If the stick is not treated and is exposed to water it will avt as a wick. Ending in a wet head and a ruined match. Another option is to go the expensive route and purchase wind and waterproof commercial brand. The best of which are lifeboat matches.

Either a sealable, meaning one with an O ring gasket, match container or vacume packing bundles with a sealing machine is a good method to kep them dry.

If you are like me, a belt and suppenders type, you water proof the matches and then store them in a waterproof case just to be sure they work when thing get critical.

Because fire can be so necessary I think everyone should carry at least 3 different methods to start them. Plus the primitive skills to start them with no modern aid. I.E. several different fire by friction skills. For modern fire starting I personally do not concider matches an option. For the same amount of space of 20 matches which would start about 20 fires. 40 if you are skilled enough to split matches. For that space I can pack a disposabe lighter that will start hundreds if not thousands of fires. Even when the fuel runs out it can still act as a flint and steel source. As I am a smoker and use mine every day I carry a full one as a backup. Then there are the modern flint and steel rod or rod magnisium bar combos. Many smallere than 10 or so matches. I also carry a fresnel lens in my wallet to start one when the sun is shining.

Sorry to be so long winded I'm a natural firebug.