Only you can determine what boundaries should exist in your relationship. Some people are complete open books with their mates. They have access to each other's email and Facebook account passwords, debit card pin numbers, become comfortable with their friends to the point of contacting them or visiting them without their mate....etc Other couples are more like roommates splitting everything down the middle financially for rent/mortgage and utilities while keeping their income, other expenses, and other dealings private.
Some people feel uncomfortable or develop "trust issues" when their mate is too private. Others are afraid of "losing themselves" or getting hurt by being too open.
There is no "right" or "wrong". There is only "agree" and "disagree". Ultimately we are all looking for someone who "naturally agrees" with us on the major things in life. You can't be happy if you are uncomfortable with things in your relationship. Everyone wants to be accepted for who they are.