To avoid future conflict, I suggest you should pm the person who's work you are using/altering and wait for them to reply. I too would be pissed if someone took my artwork and didn't talk to me about it.
"I did not Copy/Paste it. That is insulting. I said I would use yours as a base template, I liked the design so I kept it. I did change the colors, contrast, and brightness of the image. Like I said, I don't care if I take something off of one client and put it on another. But no matter what, I will change something so that I don't have to give credits to anyone else."
You should still give credit even when you are changing something.
Plagiarism = "to steal and pass off (the ideas or words of another) as one's own : use (another's production) without crediting the source"
[spoiler]http://www.merriam-webster.com/dictionary/plagiarize[/spoiler]
"Shall I say this again? I don't give a crap if they look pixel to pixel. Not my problem, not your business. This is a personal theme, it looks good to my eyes so I used it."
I don't really think it's "personal" if you're sharing for everyone to see. If you're just using it for yourself and not sharing it with other people, then I guess its fine to not credit anyone.
E.g. I'm doing an essay on Sustainable Development, if I'm using another source, I obviously can't copy word for word (unless its a quote). I would have to paraphrase it. Even if I paraphrase, I would still have to include it in my citations. If I'm writing for fun and not going to share it, then I can do whatever I want. If its an assignment that I have to hand in, then you should credit.
Anyways, nice GUI, love what you did with the move types. Can I ask how you removed the box around the username and password?
^This pls :)