The UI usually maps linear motion quite naturally. In real use the control is mapped to a physical knob via MIDI, if you'll be tweaking it on the fly.
No. There are so many plugins and so many knobs that you will never have enough MIDI control panels and time to set them up.
I wanted to learn Ableton and have determined that it,s futile unless I get a MIDI controller
Absolutely untrue, but a MIDI keyboard will certainly improve the experience.
I hope you see this, just noticed your reply! Thanks for the encouragement, music production/DJing is something I really want to get into, so encouragement is extremely welcome. :) My problem when I tried using it was that the knobs were really difficult to adjust with my mouse, like it didn’t feel responsive. Am I doing something wrong?