The question is when was your last qualifying miles earning activity on your account. Miles are valid for 2 years and this validity period is reset every time you earn new miles (from flying or eligible credit card use like the AF FB Amex in FR and NL). If you had no earning activity since you earned the miles you used to pay your ticket and if those miles were earned 2 years ago or more, they will not be recredited to your account as they will be considered expired.

For your 2nd question, I am not sure and so I would prefer that other experts on this forum give you their opinion.