'How we do things' is not important for me.
One thing that matters, though, is that 'things get finished'.
Right now, p.a.imagecropping is working 'as it should' (I think).
Probably we need:
a) Just ImageEditor ported to Plone 5 and keep 'other things in their own packages'.
b) Some kind of javascript or (external) api solution
c) A 'pluggable' image editor with all kinds of functionality (which probably never will be finished).
'
I would prefer 'many small packages' to adding more 'none core' functionality… at least until 'it is working'
Edit
After looking a bit at thumbor.org: maybe something like this is more related to collective.lazyloading than an Image Editor ?
@espenmn do you have a strong enough sense of what this project would entail to begin writing up a more complete description? Take a look at last year's project ideas for inspiration on the format.