Of the three, NH is probably the closest to being a "swing state", but it's really not.
I agree with the last part of your sentence, but how is NH more of a swing state than VA and especially WI? I mean, come on.... WI can be won by the right Republican candidate, it's more elastic than people here seem to think.
No. Wisconsin is a safe D state. The GOP has a much higher chance of winning NH and VA than WI.
I don't think WI is safe D, but Trump in particular seems to be non-competitive there. We've had several polls so far and he's failed to crack 40% in a single one. Also, according to a recent GOP primary poll, 42% of the WI GOP view him unfavorably. No way he beats Clinton there.