It appears that you've left two extra rings ON TOP of the bow's back, right? You didn't remove two rings extra to get below the back, did you? Hard to see perspective in the first pic...
Either way, that pin knot in the first pic is nothing to worry about, but that two rings island around it needs to go. Make the back one continuous growth ring, without extra rings around pin knots. The tree will have naturally compensated for the pin knots, by leaving it slightly raised. That will be reflected in your bow, once you've brought it all down to the same ring.
That crooked spot near the handle is also nothing dramatic and will just add character. But again, you need to remove those islands of rings that you left on top of the actual ring that is the back of the bow. ONE continuous growth ring - not one with some islands. Although islands in a STIFF handle will not be a problem.
With a 64" stave, I wouldn't cut it any shorter to make that crooked spot part of the handle. Just lay out the handle from what you've got so far and use the true center mark for lay out. That crooked spot might become the handle fade of the bow. No biggy, but makes for difficult tillering. I presume that crooked spot is similar on the belly side of the stave? It's not a big cavity of dead wood or a knot or anything?