I do agree with the legolas vision and Usain Bolt sprint speeds, but zombies are actually pretty easy to beat with melee. You just have to strafe around them and keep your crosshair on their head.

The point of this game is not to dance on daisies, loot stuff and never ever die.
The point is to survive. If you can't look around you and be more careful, this game probably isn't for you.

Someone probably hid your body.

If you have overclocked your GPU, you should probably restore stock speeds.

You probably want to try these unofficial fixes:
http://steamcommunity.com/sharedfiles/filedetails/?id=216291078

I've played for ~ 3 days and looted multiple spots and I've never even seen the M4A1 but I've seen it in videos and such. Probably just a matter of luck.

That's funny. I can drop zombies with 3 hits to the head with a melee weapon and 15-40 with fists.

Around 3 hits to the head nowadays. It isn't that bad IMO.

I can confirm this. Happens with other melee weapons too.

You have to raise up the binoculars before "aiming down sights", otherwise the camera will still move to the binocs but since the binocs are in your hands and directed towards the ground, you probably won't see anything.