Scarf joint crack and other issues, What do?

Hey, Sorry about the long speech here.

About a year ago I bought a second hand Ibanez to learn the basics and such and I plan on upgrading/modding it so I can eventually sell it and buy a new, better one.

It is completely playable but has several issues, like sketchy pots, not the best wiring and pickups that, while decent, could definitely be better. Those are easily solvable as I'm no stranger to soldering and such and it would just be a matter of taking old pieces out and putting new ones in.

The most important problems, and the ones I'm concerned about, are in the neck. The tuning pegs have been replaced at least a couple times with different models, leaving ugly holes in the back of the headstock (I assume wood filler and sanding can solve those but please feel free to yell at me if I'm wrong) and the wood on the side of it is chipped, but most importantly: the scarf joint in the back of the neck separated somewhere in the past.

The crack looks like this, apparently there was an attempt at repairing it before . My questions are: What can I do about this issue? Could I do it myself or should I have someone with more experience do it?

 

I had heard about the toothpick trick before but only for stripped screw holes on the body, didn't think it would apply to this at all but that's surely good to know. Thanks for yelling, it was necessary.

And no, the joint is not open now, as it had some glueing done to it before. The joint doesn't flex or move even after re-stringing the instrument once and is mostly a cosmetic thing. I can feel a difference in height but it is so small I can barely see it, part of it must be the glue that was left over the crack, but the wood was definitely not perfectly placed back together, luckily it's not noticeable unless you're looking for it and it doesn't affect playability.

Over all, while looking rather ugly, is not a real problem and the cosmetic issues could be fixed with a re-finish.