I've been messing around with Pencil2D to create simple, keyframe animations, and although it works nicely, I can see how if you have an animation which is a combination of lots of independent animations (as I'm sure most animations are!) then you'd have difficulty creating that in software as simple as Pencil2D. I don't know how professional animators handle this, but I would have thought that it would make sense to create each of the independent animations separately, and then be able to import them in to the main animation and position each one freely and set their own frame rates.
I was wondering what software is available (preferably free, but trialware would be OK) that would allow you to combine several independent animations, whilst still in their original, vector format, onto a single canvas that then forms the final animation (which will be a standard video that can be uploaded to online video services)? I don't think that a standard video compositor would work because I want to be able to zoom in and out of my animations while retaining fidelity, but I'm happy to be proven wrong!
I'm working in Windows, but have access to Linux if needs be.