@ OP.
I think Live 9 would probably be the answer to many of your (prayers?) requirements . . . but obviously not without cost, or caveats.
Max For Live absolutely blows the doors off when it comes to outside comms - but Live itself is a bit of a toy / joke in many regards when compared to something as capable as Cubase. I used Cubase for many years myself . . . but my focus now is on live performance, more specifically I want to mesh the creative / generative process of writing music with being able to go out the same night and perform that music, all within the same environment.
Right now - nothing touches Live+M4L for this. Therein lies the problem however . . . since Live has had no direct competition for going on a decade now, and since the overwhelming majority of the userbase don't know any better (as evidenced by $2k Point Blank courses

), the UI is sucktastic beyond belief at times.
No "window sets" (or anything resembling same) - so get used to grabbing that mouse and resizing panels ALL THE FUCKING TIME . . . unless you use M4L and some external code to reach in and perform mousing tasks for you (which you can, and it's fun to see people faces when they see this for the first time lol!).
Swings and roundabouts.
The approach most pros take is to ReWire a real DAW (you know, one that actually doesn't suffer from timing issues) in for arrangement and editing duties, even VST handling sometimes. Less than idea, but actually quite a flexible and rewarding way to work.
Live can be run as both a ReWire Master *or* Slave, and is reentrant (can run more than one instance concurrently).
NB - I am not affiliated with Ableton in any shape or form, and have nothing to sell. In actual fact, I dislike their corporate culture with a passion. They're just Steinberg in trendy clothes.