I like the idea behind the force of nature, but I think the weapon needs a bit of minor tweaking to make it competitive. Maybe take away the -20% damage part and keep the range really short.
I can't stand the sandman, it is too easy to use--the flare gun is tougher and isn't nearly as good. With the force of nature, you have enough of a double-jump to go across 2fort. It might just be me being an ex-WoW player, but the stun is frustrating, and I feel incredibly cheap using it on someone. And nothing is more frustrating than getting stunned and being able to do nothing but watch yourself die.
I haven't gotten the energy drink, but I've watched a friend play with it. He hadn't gotten good yet, but I have a feeling that we will see it become more useful when scout populations go down and games become more normal.