I'm talking more about the post-plastic surgery as in someone post-operated

Unless there's some sort of visual cue that would hint that the character has had plastic surgery, I don't think that's something that can be tagged.

When someone post the image, but he/she don't add artist/source or copyright because they don't know (or lazy). So viewers don't know where the image came from. These sites will help them identify image source/artist/copyright:

saucenao.com/ - Pixiv image searcher, provide image source link and artist source link. It also has a few anime screenshots.
www.ascii2d.net/imagesearch - Japanese 2D image searcher (read comments if you can. It also give source).
images.google.com/ - Use this when both saucenao and ascii2d fail, or can find other image version (e.g. full image than the old one). After that, try saucenao and ascii2d again. When use google resverse image ,Chrome and Firefox give different result.
www.tineye.com/ - similar google but only useful for finding full image.
G.e hentai image search (for Firefox):
1/Install this add-on: addons.mozilla.or.../greasemonkey/?src=search
2/Install this script: userscripts.org/scripts/show/124432 .Tutorial in it too.
Can anyone help me add this to FAQ ?

How do I change my nickname?

You can't.

Couldn't help but notice a lack of forum games here. Does that mean tjat forum games aren't allowed here?

This isn't the kind of place for that.

We've had forum games in the past, but they generally tend to die out and go nowhere. They aren't strictly disallowed, but there's a pretty big chance that people will not play them just out of disapproval.

So... how do I fill in the About Yourself section in my profile?

You can't, not yet anyway. Maybe someday we'll get that working.