I have a bass that I don't really play too often, but every now and then I like to whip it out and have fun. However it isn't well taken care of and I've noticed a few problems and I was hoping someone could tell me how I could fix these problems before I decide to give up and take it to a luthier. I'm confident I can fix it myself if I know what procedure to take.

The neck has an excess forward bow.
Sound from the strings is weak and dies quickly and some parts of the neck (especially near the nut) barely resonate at all.
Action is very high in the middle of the neck and buzzes horribly when played.

I'm sure the above can be fixed with adjustments to the truss rod and some new strings but what concerns me is that when I tilt my bass backwards (towards my body with the strings facing the ceiling) anything I'm playing abruptly ends in a very loud, very worrying buzz. This is not true when I tilt the bass the other way. I've also noticed what seems to be some small cracks (very thin and small but I can feel them as I'm playing up and down the neck) in the middle back of the neck.

Is this a sign of horrible things to come, or is it just wear and tear?
I'm sorry I'm not very knowledgeable when it comes to these things. Thanks.
I don't need a sig....
I can't really say anything without the guitar in front of me but my advice would be to take it into the local shop and have a tech look at it for you. You don't necessarily have to pay them to do anything, just ask for some advice.
The cracks in the neck worry me, but the backbow can be solved by adjusting the truss rod. I'd adjust the truss rod first and then see if the problems go away. You may need to have a few frets leveled.