Initial thoughts: I like it. I dunno if its balanced (yet) but I like it.
I'm growing warm to the idea expertise dice for martial PCs. I still think the damage/cool stuff abilties of paladins and rangers can be handled via smite/favored enemy and spells, but for monks, fighters, rogues, and perhaps warlords its fine.
I like the frickin alignment restriction! All WotC needs to do is introduce a "martial artist" specialty (which dovetails with the monk as default) and you can have all the fighter and rogue martial artists you want. But if you want ki abilities, unarmored AC, and the like, pony up and play a lawful PC.
Do the same to druids, paladins (esp), barbarians and assassins WotC!
Bear in mind the monk, sorcerer and warlock aren't as customizable as fighters rogues or clerics. That's fine. You are "specializing" and that limits a few of your choices.