Thanks everyone. Turns out we'll have one extra night, so we'll have three nights (two full days) in Kiev and two in Lviv, so it feels like the above itinerary would work, and we'll be able to do it a bit more slowly. Any and all specific recommendations are more than welcome!
Back in the old days I might have tried to do all four cities in four days, but... yeah, that's a lot of traveling... and can't put a kid through that.
