So I have a Thermaltake VH6000BWS Case, and the cable management system is very good.
The only issue is that the cut out holes inside the case are very sharp, and I was wondering if there were rubber padding or grommet-type things (I heard this term in a video) I could put on it so it wouldn't be that sharp.
1. Are you working with these cases a lot and want to reduce the sharpness?
IF so get yourself a dremel and before you install anything into the case run the dremel over the drilled hole to soften the edge.
2. Are Hard Drives or Optical Drives causing vibrational "noise" because of a lack of smooth fit into the pre-drilled holes?
IF so then what you want to get is a grommet or rather a "washer", or the cheap version is a piece of felt. Cut the felt into a tiny square and punch a hole through it with a pencil or pen. Then place the felt on the out side or inside (you won't know where the vibration is coming from so if it still makes noise change the placing of the felt from outside to inside and vise verse.) and screw in the drive. In the rare case you still have vibrational noise (I had this once with a sony DVD/RW) put the felt on both the inside and outside.
You can get cast of felt "rags" from your local drapery manufacturer. They usually will give them away since they are cut to small to use in anything. Alternatively you can buy felt cheap from a fabric supplier or even possibly from an arts and crafts store. It's much cheaper then "specialized washers/grommets" and IMO it works better.