Once married we will apply for her FLR visa. How will the change in address from her Fiance Visa place of residence to our new home affect our FLR application?
Basically I think your answer is it won't, assuming you meant that you will be living at X place when she applies for her fiancée visa and another place after you get married.
Also, will me initially living at home prove to be beneficial on her application for a fiance visa or should I move into a new residence before she applies??
If living at home, you will need to prove that she can live there (permission from your parents assuming they own, or the landlord if they rent) and that the home is big enough to safely accomodate you and your fiancée (basically if it is just you and your parents, then two double bedrooms should be sufficient). If there are hords of people living with your parents and you sleep on the setée, best to move first!
Also, not to imply that if you are living with your parents that you are under 21, but since November both of you will have to be 21 or over. I know that lots of folks move back in older then 21, but it was just one of those things that might be applicable to you.