**DISCLAIMER** I ain't no expert: But..., the lighter colored wood is maple, and it is spalted. This is a very desirable trait for guitars since it stains well and makes a gorgeous finish. Hence the reason I recognize it easily. Can't attest to the darker wood, but looks like hickory to me. Hickory ain't used for guitars so I don't know much about it other than I like it in my smoker. Safe to use for BBQ? I will leave that to more knowledgable folks than me. Who knows about your specific load of spalted maple. Spalting looks different in different woods so if you run a stick burner you're bound to have thrown a spalted split or two in the firebox. But again, I will defer. As for the funky stuff on the bark, I'd hatchet that bark off before using the piece. I typically remove the bark for my splits before I toss them in the firebox unless a particular split is stubborn.