You might consider a radiator guard, but I ride mine stock. I've done 3 dual sport rides (and fell off a couple times), but was mostly mud so no biggie. I would think the plastic skid plate is adequate unless you ride lots of rock gardens. I also have a Yamaha 250 and a lot of owners are going to plastic skid plates for those. They say it's quieter.
Bark Busters type hand guards are nice, but once they get pranged it's hard to bend them back. The plastic ones flex, but not as much protection for your hands if you actually hit a tree, which is what I think the metal ones are for.
I've never really seen case guards for dirtbikes. Only for more street oriented motorcycles.
Mine has over 3200 miles now and the motor has finally smoothed out over the last 500 miles. I can still tell it's a single, but barely. Me happy!
Straight ahead and faster -Bo Weaver 1970
"There I was..." -Griffin Niner Three Hotel
"One day closer to a parade..." Jonny Gomes, spring training 2013