Here are a couple drills I find very usefull in getting comfortable in the pipe.
Rock in'and out. Drop in on one wall, set your edge, carve across the bottom, and go up and out onto the deck of the other one. Sounds simple? Try it. You may have a few interesting moments. It will really help you to judge your speed.
Here is another one. Try this after you feel comfortable dropin' in and out. Drop in, and carry enough speed to get all the way up the opposite wall, so that your feet are just at the lip. Remain calm, and drop back down switch (twins please!). Very scary at first, it will go a long way in terms of comfort in the pipe, especially when you try a 360, or a straight stall air.
Get comfortable rolling in with some speed, not just from a standstill. You can use a "pre jump", or just retract your skis, and roll those tips down to get early contact with the vert. Do not air of the lip. Get your skis onto the snow as soon as possible, or keep them in contact as you roll in.
Once you are ready to go out, be sure to look at the sky, not the lip.
Also, try to avoid planting your pole. It is a nice balancing crutch, but really limits how far out you can get.
Pump yourself up the wall, and be sure not to extend into the pipe when you "pop". This could lead to landing in the flat at the bottom of the pipe, instead of early on the transition.