1.) This is perfectly normal. A slightly raised idle is alright, as long as the tires weren't going full-out. This is caused by clutch-drag, and again, is normal. As long as you had a nice sized puddle of unburnt oil on the ground (something that looks like an Exxon oil spill), you are more than safe.
2.) Lean the upper (main) needle just a hair. Just enough to keep it from stalling. Keep an eye on the temperatures when doing this. It is perfectly normal for the engine to be overly rich from the factory; HPI sets them that way to lower the risk of con-rod-popping. Doing this, you'll find that the engine can idle slightly lower. However, don't get carried away with leaning the engine out too much.
After the first 6 tanks or so, the engine will start to come around. Don't give up on it. Stick with it, and you will enjoy it for a long time to come.