Re: Can I manage Ads for mobile Campaigns only.
No and yes....
No - you cannot separate out mobiles as devices on the new enhanced campaigns - and even if you switch back to the legacy format you're only delaying the inevitable and wasting your management time since you will have to do what you need to do now in a couple of months in any case when Google switch everyone over (screaming and kicking).
Yes - because you can adjust the bids for mobile. You cannot completely stop the ads appearing on desktops and tablets, but let's suppose that your average CPC is around $1. You're not going to get many impressions (on any device) if you bid at 25 cents.
So bid a t 25 cents and then adjust your mobile bids to be +300% - which is the maximum. Now you should start to see impressions on mobiles (because the bid is back up to $1 through the adjustment) and still practically nothing on desktop and tablets....
It's a clunky workaround - at least that's how I see it at the moment, but I think as I get more used to approaching things this way, it will become more "natural" to me.
In any event, as I said above - I ain't got no choice!