You can't build a DM mode on a foundation of loose sand, which is what an Alpha is.
I would not expect to see DM/Adventure Creation tools available until after the game is feature-locked (no additional new features will be added). Trying to put them in earlier just means a lot of pointless extra work changing them constantly as the alpha and beta get revised.
Yes and No. While the DM tools may rely on a solid foundation of gameplay, as that should be it's focus - allowing the DM to tweak and adjust gameplay "on-the-fly," I think the Adventure Creation tools are very independent and are focused on visual and audio creation of the story.
I fear a repeat of the lost-opportunity that D:OS1 toolset brought -- a toolset that (almost) only a Larian developer could use that saw a grand total of (maybe) two(?) independent adventures/stories created 6 months or so after release?
The Adventure Creation toolset needs to be easy enough for a non-technical, non-script-expert, non-programmer to be able to create stories that don't require a live DM and can be shared with the ease of merely pushing a "publish" type button.
And those of us who ARE script-monkeys would really like to see HUGE improvements in the actual script "language" to make it a "real" language and not some weird state-machine with side-effects that change variables based on their positionality.
...and a pony. ...a Unicorn pony. ...and I want it now.