Regarding your remarks about the M6, remember that we have not even seen an uncovered F32 4 series yet, nevermind an F82 M4. That is to say that, the larger coupe really needn't be part of the conversation until we actually have something to compare it to. I strongly doubt that the F32 and F82 will look anything other than spectacular, especially the latter.
Regarding the F30 3 series, I can see what you are talking about in the front end design, but here again, lets wait to see what the F80 brings. It will probably retain the headlights and your "cross-eyed" look, but the rest of the front will be entirely M (and probably look much like the M5).