Yes, politicians and reporters could potentially blow this out of proportion. There are still a lot of people who believes that computer games are for kids only, and they might very well think of this as a pro-smoking campaign directed specifically towards children. It won't matter if the game is directed to an older audience. This kind of stuff is sensitive.
No, if it's rated M they really can't say anything as long as the tobacco companies didn't "fund" bethesda in any way.
And like i said before. Solid Snake from Metal Gear, Metal Gear 2, Metal Gear Solid, Metal Gear Solid 2, and Metal Gear Solid 4 smoked cigarettes in ALL OF THOSE GAMES. and in each one cigarettes were an equipable item. In Metal Gear Solid 3, and the PSP Metal Gear Solids, Big Boss (the main character) smokes and can equip Cigars
There's no reason why Snake can smoke cigarettes in an M rated game and your character in Skyrim can't