No options like that are available for this forum software unfortunately, neither by default or as a plugin, so I wouldn't be able to do that without resorting to writing the plugin myself.

The avatar does show a little larger for the first post in the discussion, and of course even larger on your profile page.

It's been deleted. Give me a word if you still have problems editing your profile, the forum may cache something that needs cleaning.

Seems to be an oversight in the template. I'll mention it to ProFantasy to look into.

I don't think the edit option works on lines, only on polygons.

The color is the view window color. You can change it from the View menu

Yea, I know. There is something that doesn't behave the same here as on my test server, so gallery uploads obey the same size limits as attachments. I am looking into it, but for now you'll just have to wait with the larger images.