It is not a problem to have two different addresses in your M&M profile, but I also never had a problem with tickets being mailed to an address that was different from any of my M&M profile addresses. That is, unless it was an award ticket. In that case LH only sent it to my M&M address. The M&M Visa is independent of the M&M address, all you need to maintain for it is a German bank account. Even though I live in the US, I maintain such a German bank account, and my Visa statements are sent to my US address. The bank has no problem maintaining the German account with a US address.