Is it ok to pump milk in advance?

Yes. Make sure your baby is well fed and you are a good milk producer.
Absolutely . If you are planning to go back to work or have times you are separated from your baby freeze any extra milk you make. It can be stored in a sterile container for 3 months in a defrosting freezer or 12 months in one that is frost-free.
Yes. Sure, but really unnecessary and not likely to work very well. Your body has a plan - whoever created us designed it in a very specific way. You are not likely to be able to cheat that plan with any great success and its completely unnecessary. Breastfeeding will go just fine especially as you commit to making it work for you. Feeding early and often and not giving up when it gets hard.