I understand your worries, but I think it’s a misunderstanding that samj is wanting to remove any functionality/features.
MB’s users in particular would kick up a huge fuss if there was even a hint of that happening, so I think we can relax on that front 
As for the 2 panes let’s wait and see what UI mockups samj comes up with before we pass judgement.
I agree that the concept (before + after / your files / database items) is solid, I was just disagreeing that it’s ‘self explanatory’ which I think is what you’re saying anyway re. needing text descriptions as well.