The App screen is something that is going to have to be rethought from scratch. I like the idea that Watch faces are app launchers themselves, with complications serving as information as well as a shortcut to the app. Like in iOS, you can have multiple home screens as you can have multiple watch screens in watchOS.
Perhaps a grid of app icons that you look for and tap to open, don't belong on the Watch.
Apps on watchOS should be designed to fall into these categories:
Siri launched: Hey Siri, get me an Uber.
Complication launched: Weather shown on complication, tap to launch details
Notification launched: Your team scored! Tap to launch details
Dock launched: Apps with glanceable information. Tap to launch the full app
A new crown scrollable App screen could be placed to the left of the leftmost Dock app. That would be a way to see all apps currently installed, but not the primary method for launching apps.
The Dock button makes the most sense for launching apps, not the Digital Crown which is best seen as a controller for in-app interactions. I think that it would make sense to turn the Digital Crown press into a "select" action. Turn the crown to move through options, press to select one. A lot of people actually do this from what I've read (I sometimes do it too). It's intuitive to press after selecting and it's a bit jarring when you're kicked out of the app for pressing the crown during a selection.