Harescramble setup?
 

Again I'm new to quads, and I'm 45yrs old lookin to "ride HS" to get some dirt in my hair and a little exercise lol. I bought a like new 2003 ltz400 and orderd bumper/full race nerfs, it has new razor tires all around and that's it. Besides the required tether switch is this enough to race a old man class? I know to get skids and shocks but I'm really thinking at my current ability it would be wasteful???
Race cut fenders look cool and I see the benefit from being able to see where your wheels are but is that a mx thing or helpful in HS?

Do NOT race cut the fenders. Any muddy sections on the track and you will want all the fender you can muster. As it is, watch the pros go through water sections and stuff. They go through just slow enough not to splash water on the controls. Hand guards and even the gauntlets can be a big help here too.

As for skids, yes, get the best you can afford. A virgin track will develop ruts big enough to bottom out on after a few laps. Event organizers also like to throw rock gardens in the mix. I have seen machines sidelined within the first mile from this stuff. I have had really good luck with the PRM swingarm skids, although the round disk style gives you a little more ground clearance. Just make sure to protect the brake as well. I would also put a poly belly skid on it. They hold up better than aluminum if made right, are often cheaper, and slide over obstacles better as well.