I was a Cub Master for three years, I have been an Assistant Scout Master for five. I had had the please of being an adviser on a Philmont trek.
As far as training goes I was an EMT for 7 years and currently teach OLS (outdoor leader skills) and OWLS outdoor WEBELOS leader skills), WFA (wilderness first aid), and Orienteering at our University of Scouting.

It is not what I carry that decides the outing. It is what the boys carry that is the key.

There is noting you or the boys can carry that is lighter or more versatile than knowledge.

I made a point during my time as Cubmaster to lay the foundation with the boys starting as early as possible. Even Tigers can impress us if given a chance. Although the boys should carry no more than 10% to 15% of their body weight in their packs they can do there part and learn to use the ten essentials. I carry a full complement of the ten essential systems with me on every outing. I ensure the boys at minimum have enough water to avoid serious problems and the key systems to cover our plan and the weather.

The earlier the scouts and their parents learn the personal in personal first aid kits and personal gear the earlier they will be able to truly enjoy their time outdoors.

I was given a 2 up 2 sided set of medical forms what I became Cubmaster and I have kept current medical forms with me for all youth and adult leaders since. I also have the parents provide any listed medications in individual snack bags per administration and in a clearly labeled larger bag with the scouts name. The key is knowing the parents wishes and having them is writing on the scouts forms. You are wise to try an steer clear of becoming "that guy". It sounds like the unit has a valuable resource available. Take the training you can and continue to help out where needed. One hour a week only works if we all do our part and accept the assistance available within our units.

Yours in Scouting,
Jim