if you have a character that is dodging and attacking with a sword it might be a *big* difference if frames are cropped or not.
...snip...
You want to keep the anchor point steady while the animation moves around it...
Correct. Posemotion: Imagine a standing character crouching down to do a foot sweep, standing, then doing a high roundhouse kick. The size of the art in the frame changes dramatically.
Right now C2 also only has bounding box collision so empty space around the player will also collide, but you can work around that with a hidden collision sprite, or just wait until we add collision polygons.
I look forward to seeing this implemented; right now the bounding box collision issue is keeping me from really diving into Construct2 full force. In the meantime I am working on my design, art, and C2 tutorials.
I don't want to sound like an advertisement for Texture Packer, but I bring it up because it has a lot of nice features and was so easy to use with Corona SDK. (I ditched Corona due to their sprite libraries being completely broken.) I was hoping for similar interop with C2.
FWIW: I run my pngs through Photoshop's "Save for Web" interface to trim them up.
Thanks again for the great discussion.