A lot of people will put a bowtie patch to hold the split from getting any bigger. You could mask off the crack so the epoxy only goes into the crevase and then sand it flat. That shouldn't interfere with the oil and bri-wax finish. The knot holes I would mix some tinting color to bondo to match the finished color and fill them with that. The color would need to be a little less red to allow for the red in the hardener when you mix that in. The residue around the knot should sand off on that.