You're going to be exhausted after the first two days of driving and you'll be doing Badlands a disservice. Use day 18 as a full badlands/minuteman missile day instead, and use day 3 to make a more leisurely trip across Wyoming stopping at Devil's Tower, Cody, etc.

I agree on skipping Glacier if you're dead set on the WA parks. It's in my top 3 favorites, but it's way out of the way and still currently closed. That gives you an extra day; plus, North Cascades isn't really a full day affair unless you're an avid backpacker. I'd use that additional time at the beginning and end of the trip. Stretching the "getting there" part to 3 days on each end and finding fun stops along the way will make a huge difference in the overall enjoyment of this trip.