1) As Copyranter points out in a post on the ad, it is a spot promoting alcohol. This is entirely in line with Motorhead's preexisting persona. Given the iconic image of Lemmy in constant possession of a Jack and Coke, it's a shame nobody making premixed Jack and colas beat K1664 to the punch, especially since, as Copyranter also points out, it is a French beer, of all things.
2) The luxuriously slow blues version of "Ace of Spades" Motorhead plays (to fit with the campaign's slogan) has an understated swagger well suited to a majestically grizzled and still phenomenally badass rock legend of a certain age. Put in the terms of a well-known joke, Lemmy is the old bull who suggests walking down the hill. It also sounds pretty great.
3) I don't know anyone on Earth (or from anywhere else) who can tell Lemmy what to do.