Now in my 10th year as a Scout leader with my son, going from Tiger Cub to an Eagle Scout about to receive his sixth Eagle Palm, I've seen what I think is the full spectrum of Scouting.
My first thought is to make sure that you don't try to teach a Cub Scout too much ... to save some of the fun stuff to teach them the higher-level skills in the coming years.
At least in the U.S., in general, Cub Scouts do not work on fire starting skills, nor would they be treating water to make it potable. Knife use comes in the later years of Cub Scouts - which seemed to me about the right time.
As for gear, I've yet to see better advice for kids than what Doug Ritter has posted on equipped.org at the Survival for Kids link:
http://www.equipped.org/kidsrvl.htmWhen I taught survival skills to my son's Cub Scout den I also focused on the hug-a-tree notion of survival. The boys' job was to stop, make themselves as findable as possible, stay put, stay warm and dry, listen for rescuers, and if they hear any rescuers, blow on that whistle as hard as possible. I specifically warned them to NOT try to walk to try to become unlost, cross waterways, or climb trees.
I repeatedly told them that they needed to understand that adults WILL be out looking for them. When adults get lost there may or may not be people out looking for them, but when young kids get lost their parents will quickly be doing everything they can to find their child.
Their main way of being found is to find an opening (though I pointed out to them that trees can cut the wind and help them stay warmer), using the whistle, the LED light, and/or the bright bandanna.
One of the hug-a-tree recommendations is to capture a shoe print using foil. While that's a cool idea, I'm not sure how practical that is. I tend to think a more practical idea would be for parents to simply take a digital picture of the soles of children's shoes when first purchased.
One last thought is to make sure children wear brightly colored clothing (including jackets). The current trends for folks to wear dark clothing or even camouflage clothing is not a good thing in my mind. Heck, even when I camp now I tend to prefer a brightly colored tent so that I am more likely to find it when I walk about from the campsite - especially where forests are fairly dense.
Not so much for survival, but Cub Scouts is a good time to start introducing them to a compass. I've mentioned this before here, but when my son was about mid-way through Cub Scouts we started doing a pin-the-tail-on-the-donkey type game with a compass, a white sheet, and some post-it notes. We'd show the boys that the needle on the compass always points north. We show them how to point the compass at a target on the wall, rotate the bezel to box the needle, turn around at random, and then they can carefully turn their body to re-box the needle, which now has them facing the target again.
Then we redo this, but before turning them around we put a sheet over them, tell a story about a heavy fog rolling in, and then rotate them around and tell them to use the compass to turn and face the wall, and then walk to the wall and place a post-it note with their name on it on the wall. When all kids are done doing this we compare where all the notes got placed. BTW, we found it best to have an adult walk near them to help prevent them from running into tables & chairs.