Use the answers that are to your advantage to impeach the credibility of the person answering the interrogatories. You can have the party reconfirm the answers when taking the deposition of the party and then ask about the inconsistencies.
You need to speak with a financial advisor to be safe. In general money for pain and suffering damages (non-economic damages) are not taxable. Money you receive for lost wages and/or loss of earning capacity from personal injury case is a taxable event.