Great idea.............I too keep the essentials handy on a daily basis. Mine varies somewhat from yours in that I always keep a weapon & ammo packed, med. supplies, and such. Being from Texas also, I need to have more prep. for water than possibly some others might. I don't like the buttpack carry very well, I prefer the shoulder bag from the same folks that made your bag.............and I like to carry on my left side rather than my right ( I am right handed). I use a cane for extended walking, and it has numerous other benefits as you might imagine. Remember............."the more you know....the less you need.
Good luck....................Mike