Always hire a lawyer. Always.
My feelings (for entertainment purposes and not legally binding) is
1. I don't think that visa works for this - you're an overstay.

2. It shouldn't. My sister filed when she got married and nobody came after me and I'm sure I'm in worse shape than your family.

3. If you're an overstay, no. You have the gift of readjusting your status. It will take about a year to get your green card and after 3 years you can become a citizen and file then....all goes well, in 4-5 years you can apply for your mom and the paperwork to go through. Good news is she's immediate family. Your sister is not however so if she's going to be older than 21 in 4 years, it'll take about 13 years after 4 years so she can get her green card through you in about 17 years...assuming the laws stay the same.

4. Once again, hire a lawyer.