The level crossings look alright to me. They're a bit funny at first, but if you think about it, it makes sense. The train bed is raised, and then has the raised center bar to provide a magnetic point for levitation and directional stability. A road vehicle couldn't hump up across those without impeding their purpose - so they drop all the way to road grade. Only the center bar is there, but at a lower height so you get levitation but not propulsion and directional control.
Of course, in reality this would mean the train is literally just hopping between two segments of track at a level crossing - which would probably physically work given a straight-line runup, calm weather and sufficient speed, but more likely would make the whole thing so impractical it would only be solveable by not having level crossings at all.
... Another hilariously impractical possibility would be having the entire center bar embedded in the road and raised up as the crossing gates closed. You might be able to do that in TTD, actually - make it part of the rear signal's sprite.
Your last idea could be cool, but yeah, as I said before, I don't believe in level crossings for maglevs at all anyway, so it's not a major part of my focus. If someone else wants to make them I'll include it and of course give them credit, but don't count on me improving them at all.