Yea none of these features are crucial at all.
The price graph badly needs a fix, because it is near useless right now. Ideally, mousing over the line would show time and price and their respective axis. Barring that, and much simpler, another screen listing time, prices and volume would do the trick.
We already have limit orders, and they work fine, except there is no reason to make it more difficult to cancel them or change limit prices.