You shouldn't be ashamed, it's okay. I do think that the orange house logo looks better, but unfortunately because it's fanmade and because we already have an official logo, we can't use it.
Fanmade logos are only allowed if 1) there's some quality control to them (they can't look terribly awful and they need to be similar to the original logo) and 2) there's no official logo available, which unfortunately applies to this case as there is an official logo, and replacing that with a fanmade one would be akin to rewriting history.
Mistakes happen, you're fine, and I'm sure you thought it was official in the first place. Just wanted to clarify is all.
I see, but I think they should be allowed to stay for consistency sake. Most other articles that I've seen include the flag icons for dubbing studios, and the only time I think it would be unnecessary would be if you used them next to people's names (on the main infobox).
They may not be required if they aren't there but removing them doesn't really help with consistency.
Actually that logo is used for distribution for China, this dub first aired on Nickelodeon Taiwan (Southeast Asia), Nickelodeon always use simplified Chinese for Taiwanese dub, because it's more popular in China than in Taiwan, Nickelodeon don't have mainland Chinese dub TV shows since 2014.