Welcome to forum @DorianGrey.
“Pinegrow Interactions” is a visual interface for creating various types of interactions currently using Greensock’s GSAP 2 animation library under the hood along with ScrollMagic (until PGIA is updated to the latest GSAP 3 and ScrollTrigger).
Due to the visual nature and the chosen implementation approach by Pinegrow what you described is just how it is. Allowing people a visual approach to things can come with certain other drawbacks as you described. But you can always use GSAP directly in your projects without “PGIA” if you need a cleaner more maintainable approach for your projects and source.
Not really that I recall? But there have been a few threads - Thread 1 , Thread 2 - those are perhaps the closest recent mention, aside from various random comments you may find here and there. Its hard to say what the next major release of “Pinegrow 6” will bring but as a major release it should offer many new abilities and features all across the app, well hopefully.
No, none presently in the sense of how tightly Wordpress abilities are currently integrated. But its hard to say what the future may hold, for instance there was even talk of a design oriented app in development. So its hard to say what all may come next.