This could definitely be realistic with the scenario of trends continuing into the future. However the chances of trends completely continuing on for 25+ years in unheard of, and definitely isn't realistic. There's a few objections here like why does Montana become a swing state and why does Michigan become a republican state before Minnesota, but overall, this is a good prediction for the set scenario . Of course we can't predict the future, so this won't be a realistic map, but its fun to play around with it.
No. Stop. There are too many issues for me to break it down entirely, but for starters, NH is solidifying with the rest of New England, not moving away to the right.
What else? I think in many of these maps, he's thinking of whites becoming more republican and non-whites becoming more democratic. If so, New Hampshire does make sense, and states like Georgia, Texas, and Arizona make sense. What states specifically do you object to the most here?