1. You CAN touch her...but seriously, she would prefer to be left alone. While we can't fully comprehend what they are going through, I believe the shedding process is probably very uncomfortable.
2. The only downside to feeding during shed is that they may refuse. If you don't mind taking that chance, then go ahead and try. Some snakes don't care and will eat at any time.
3. It can take as long as a week or so. The first signs are the pinking belly, as you've noticed, and sometimes the skin looks drier. Then they will turn very gray and their eyes will look like blue-gray disks. This phenomenon only lasts for a day or so, though...sometimes two. And then it clears up. 3-5 days after the blue phase clears up, they will shed out.