Ableton Forum

Borrow a decent interface to check, and a huge amount of your problems will go away.

Seriously.

All I can say is that you're not alone. People keep giving me the advice to not use VST3 plugins in Live, but I have thousands of dollars invested in my VST synths and effects. I love them, and don't want to give them up. But yes, the issues I've had with Live are so numerous that I've had to quit ...

It's a known issue when the audio driver disengages from the OS and an audio program is running. I've seen it off and on in several DAWs over the decades I've used audio software. Unfortunately, Focusrite interfaces are the worst for this issue. Make sure you're running the latest OS and driver ...

You are correct. Live tracks are exclusively either MIDI or audio. I confess I don't understand how one would edit MIDI on top of audio or vice versa.
Live does have idea of an External Instrument which is placed on a MIDI track and manages the connect to an external MIDI controller audio source ...

It's why I don't use Live as my main DAW. I use it as an "audio playground" staying with the built in plugs and M4L devices. When I get an idea going, I transfer it to Cubase and do my mixing and adding of 3rd party effects/synths.