Very likely there is nothing about the spine that really needs fixing. Heel could use a little work, yeah. And you need a bit of the rolling x for that gently smiling edge. You are just honing it flat, for your sharpie test, which is why you have good contact along the central portion of the edge but not heel and toe. That would wirk fine, for a straight edge, but not a smile. Try your sharpie test again, but this time with a finger just barely pressing the edge to the hone near the heel at the beginning of the stroke, and gradually moving the pressure to the toe end with another fingertip as the razor travels along the hone. You will be rocking the pressure between the heel and the toe. Just one stroke, then have a look. Do the other side, have a look. Better? Do a couple more, to get the hang of it. Then try to do the same thing, but without the fingers, just using the one hand on the tang of the razor to roll the x. Be sure to torque the razor slightly so that the honing pressure is properly shared between spine and edge, and not all just on the spine. It's a lot to remember all at once, but it will come natural after a while.
My own personal way is to roll the hone under the razor, not the razor on the hone. But I hone in hand, and when honing in hand, rolling the hone is easy and natural.
Take this or leave it, but I always recommend that beginners hone in hand. It makes regulating pressure a lot easier. Razor and hone are just out there in front of you, as if floating in space, and they come together like two spacecraft docking in the void. Razor and hone find their own alignment. This short circuits many common beginner mistakes. It feels awkward for the first minute or two, then it will be like Ah-HAH! when it comes together for you. I think a lot of new honers try too hard to control the blade with two hands, and it often backfires.
<EDIT> You might also consider painting the spine's bevel as well as the edge bevel, when you do your sharpie test.