All advice given below is general and may not be the best advice given the fact that I have not seen you ski. Nonetheless, I will give it a shot.
1. Your feet should not be locked together. They should be about the same distance apart as they would be if you were standing normally with you feet facing straight ahead.
Feet locked together is not "expert" skiing - it is not a functional stance and will hurt your skiing.
2. Short turns will not be pure carved turns unless you are on short short shapes or parabolics. Some skidding will have to happen because the turn is shorter than the natural turn radius of the edged ski.
3. Think about how you move when you want to change direction when you are playing some other sport. You push off with the outside foot and lead with the inside foot going in the direction you want to go. Skiing is the same. Concentrate on getting the inside ski
going in the direction you want to go as soon as you initiate the turn. Think about rolling the inside ski up on the little toe side of your inside foot to start the turn. If you learn to edge the inside ski when you initiate, the ski will naturally pull you into the turn. This will be easier to do in longer turns first, short turns require more timing and practice before this becomes a part of your skiing.
If you think about this, you will also see why having your feet too close together is bad. It actually prevents you from leading with that inside foot.
Although I'm not a professional ski instructor (like Otto), one suggestion I have in addition to his is to check where your weight is placed. My biggest problem several years ago was keeping my weight too far back (I leaned back while skiing). I was essentially using only the portion of my ski from the tip of the boot back. After some pretty intense training, I was able to shift my weight over the top of my skis and initiate turns using the whole ski. Learning the shift process took a while - one of the keys was to keep pressure on the front of the boot at all times (i.e., push your shin into the tongue of the boot). This will help you control the whole ski and get it on edge. Also, I can't agree more with Otto - you don't want to have "glue boot." Skis should be about shoulder width apart for best control and carving.