Blending/semitransparent alpha for TGA/PNG

I exported TGA exactly as i is showed in great tutorial, but still there is small outline (I guess it’s because of TranslucentUnlitSpriteMaterial, but not sure how fix it).

Original file is here: https://drive.google.com/file/d/0B0uYVWhdF5DcUUFqRWY4ZmtoNXM/view?usp=sharing

Can someone check it and tell me if it is exported correctly?

Also there is strange compression. I mean that artefacts like high compressed jpg. Is it possible to turn it off. I want best quality that is possible to render (like 100% in original TGA file). Thanks.