[Ed G.]

For #1 I'd say a wheel weight may have fallen off. Try having your wheels balanced and getting an alignment if balancing doesn't help.

#2 The very left 4H button should always be on. As cdmintmi said you are always in 4 wheel drive.

#3 Sounds like you might need a tune-up. This can also happen if you are in the wrong gear, say 3rd when you should be in 4th or 5th.

Hope this helps, Ed