Looks like this is pretty well covered. My thoughts are, the more protection, the better. I have all the essentials, as well as a neck donut and the Camelbak. When I go out riding, I look like I'm about to take on an army of linebackers with bad attitudes.
Do yourself the favor and at least get some knee guards. Braces are one thing, if you need them for support, but the guards will save you from those small impacts, as well as some of the higher speed tree hits etc.
A side note on the insurance thing. Some sound advice I got from an old guy that sold insurance for years ... "remove as much, if not all of your gear before you go to the the hospital, and NEVER tell anyone, doctor, candy striper, aide, or insurance carrier that your were riding a dirt bike when you had the accident!" My favorite is "I fell off the roof of my house while cleaning the gutters"
As said before you WILL have some crashes, unless you are phenominal in your riding, in which case, I look forward to seeing you grace the cover of all the dirt bike rags!
Have fun and be safe, the price of the protection is minimal compared to the cost of fixing your body.