A few quick questions about thank-you notes:
1. Do thank-you notes need to be addressed as formally as the invitations? That is, if I addressed the invitations to "Mr. and Mrs. John Smith" or "Mr. John and Mrs. Sue Smith," can I just address the thank-you to "John and Sue Smith," or should I stick with how I addressed the invites? I suspect the world won't end either way but I'd appreciate any input

2. According to TheKnot, thank-you cards for gifts received before the wedding are supposed to go out within two weeks of receipt of the gift. Particularly if we have guests traveling from out of town, would it be better to wait until after the wedding, even if that is more than two weeks away, so we can thank them both for coming and for the gift? Or should we send the thank-you out right away, thank them for the gift, and say we are excited to see them at the wedding? Would we need to send out another card after the wedding thanking them for coming?
Thanks in advance for your help!