I've run into a few issues when I import textures to Unity to be used as sprites.
Ideally, a texture should be set to Non Power of 2 = none in its import settings, and it should not be distorted.
Here are problems I've run into. Wondering if there are work-arounds:
1. If the texture is non-square but does have power-of-two dimensions (for example, 128x256), then Unity forces it to be square (the NonPowerOf2 settings is grayed out and set to ToNearest), and it will be distorted into a square in the SpriteCollection. This may be more of a Unity problem than anything else.
2. This is just an annoyance. Most of the time, non-power-of-two textures are imported with the Texture Type set to Texture, so I have to manually change it to Advanced and change the Non Power of Two setting to None. Can this be automated somehow by tk2d? Sometimes new textures do get imported with the settings I want, but I'm not sure why. For now I'm just going to write a menu command that fixes texture settings for me.