Confused on why I would degree a cam with a non adjustable setup
 

Oval out the holes and use an offset bushing on the pin.

The whole idea is to have the cam set up exactly as the cam manufacturer planned.
without doing this you may not get everything you paid for.
don't forget to check your V/P clearance. ( valve to piston )
don't just use a dial indicator - USE CLAY
The clay will show you the side clearance between the outer edge of the valve and the eyebrow on the piston. ( valve cut out of the piston )

The hole in sprocket should not be 'oval out', you drill to a larger hole size that matches the OD of the offset bushing. The bushings come in 1deg or 2deg sets. With your existing sprocket you will need to setup in a mill and use end mill to cut the hole. A drill will not work very good when trying to drill because of the slot in your existing sprocket. You may want to consider a new setup all together.

How many hours are on that gear set and chain ?? looks to be some slop on the left side

The point is you would know if it was correct or not. Then you can decide if you want to do anything about it. If it is far enough off it will affect performance. Just depends on how good you want it to be.

As far as the chain being loose it has been my experience that the big single roller chains are all that way. The first 502 I did years ago was loose so I ordered a brand you set from GM. It was exactly the same. I have tried different brands and they all seem to be the same. I will say that they don't really seem to stretch any more after initial run in.