I ride 22/25 psi on street and 12/15 on dirt. I also am looking into getting a kenda or shinko for the front. Should be less "slippery". Sorry to hear about your leg. I had a bad fall 2 weeks ago got a bruised hip and mild concussion along with soreness all over... needed some help getting in and out of bed for a few days.
Remember, it is not going to handle like a dirt bike because of the fat tires. You can just hit a straight line while others are swerving left and right to avoid the obstacles you can roll right over. It can do banks and be lots of fun as soon as you learn how she handles. Ive only had my bike for 6 months now but i've learned you need to take it slow and build your way up to higher speeds on trails.
In relation to safety gear, it sounds like you have or will have most everything you need. I always bring a first aid kit and a roll of duck tape.
You should probably get some handguards as well. They save levers and hands, i am sure I would have broken my levers at least twice by now had I not purchased a set of them.
Heal quick and ride safe.
Remember, it is not going to handle like a dirt bike because of the fat tires. You can just hit a straight line while others are swerving left and right to avoid the obstacles you can roll right over. It can do banks and be lots of fun as soon as you learn how she handles. Ive only had my bike for 6 months now but i've learned you need to take it slow and build your way up to higher speeds on trails.
In relation to safety gear, it sounds like you have or will have most everything you need. I always bring a first aid kit and a roll of duck tape.

Heal quick and ride safe.