Cool idea, but I think it strays from the "no nonsense" motto that RAT has. One doesn't really need a walking stick. It's a bit of a luxury. A spear typically needs to be longer, but I like the ol' Rambo survival knife idea at the handle, with a compass and storage area.
Sometimes yes, sometimes no. If you never stray from the beaten path a walking stick may just be an extra thing to carry, but I find them quite useful when traveling "cross-country" on really uneven ground (scree, tundra, stream crossings) and wading through water. Excellent for providing another point of stability. Also good for stabilizing extra-long steps or short jumps.
However, I want it to be LIGHT, stiff, and STRONG and don't care if it holds a knife inside. Being able to attach an external object like a stabby blade, saw blade, fish gig, or camera would be nice though.