Hi! Actually I'm already working in some of the proposed features!
I'm trying to support automatic sprite-slicing by alpha when loading a sprite containing an animation sequence but unfortunately I couldn't get it working yet.
The sprites custom tag/class has been in the roadmap for a long time and it's almost ready! Just testing the best way to expose it in the UI, at the moment I'm using a similar button to pivot-point-edit and a floating window...
Thanks for the ideas!