Yes, it is possible to connect NemKonto to your account and it is even completely free of charge. You can choose to do it as a part of the sign-up process or afterwards.
No. It is not a requirement that you need a private Lunar account to become a Lunar Business user.
If you don't have the required amount of money in your account in order to pay for your membership, you will be contacted by our support team who will ask you to transfer money into your account. If the membership is not paid within 30 calendar days, your account will be closed.