I have speedbleeders on my forks and they are awesome. I keep about 4-5 KX-KDX bikes at my house at all times (with 2 kids) and I was always replacing fork seals (even though I loosened the screws and bled of the air after each ride).
What I have found with speedbleeders is that the forks actually load up with air pressure just sitting in the carport. Each day or so, I simply walk by the bikes and release the air instantly, without any tools. I haven't replaced any fork seals since. Regarding skid plates, I would save the money and buy aluminum, although the carbon fiber is nice. You can't go wrong with either one.
JCW