how many times do reload a case, when do you throw it away.
Do you just keep using it until it fails, assuming you anealed it at some point.

and what about powder. Is it better to load up ammo and store the ammo as upose to storing powder.
How long does loaded ammo last stored in a drawer.

Depends, my wildcat formed brass gets the full treatment and I can get 15-20 loadings if I anneal a couple of times.
Common stuff I get 6-8 depending on chambering and quality of brass.
Properly stored, lose powder and loaded ammo could both last longer than the owner lives. I prefer stored as loaded.
I have loaded rounds for my 45 ACP that were assembled in 1937, they shoot just fine.

Depends on the case, the load, accuracy, and how much stretch at the webbing. Depends if you FL Size it, neck size it, etc.

I can shoot most rifle brass 3-4 times before annealing. then 3 times more. Most. I toss after that. Neck tension usually goes down, and so does accuracy

I can shoot most mild 44 mag for instance 20 times with remington brass.

Neck cracks are not the only thing to worry about. You need to worry about rim separation in front of the web. Some take a paper clip and and make a little hook and can feel if there is something bad going on towards to webbing.

You also want to keep a look out for the "donut" right below the neck. Sometimes the brass moving forward can cause this thickening in the shoulders. Again, poor accuracy can occur.

Case life is going to be affected by both the gun you're using and your reloading technique. If you over-work the brass you will shorten case life. If you load very hot loads the primer pockets will give out sooner.

In a bolt action if you neck size only most of the time and don't push the limits you can expect pretty good life out of the cases. I'm on the 8th reloading of a set of 300WM brass and haven't had to toss one of the lot yet.

Watch for loose primer pockets or a light colored ring in front of the case head (impending separation). Toss if you find either one.