Slowly, slowly is how you deal with knots. Very slowly and carefull indeed.Can't comment much about the pine. I had a huge plank once, a barn structural timber, possibly 50+ years old. There was 1 goant knot that I worked into the composition, it being too tough to cut away. Surprisingly, even as old and weathered as it was, the knot expressed some resin after I cut it.
I don't even try to take an edge to knots. Too easy to split them, and get tear-outs. Rasps, rifflers, and sanding, being careful to not get into the softer surrounding wood, are how I deal with them. For ones that are rotted in the center, I use a small gouge, and clear out the crumbly stuff.