Ok I am going to eliminate animes where the main characters ARE women (or a woman). Which is what I meant by "Arn't the main character".
Essentially removing over half your list (In Slayers Lina is the main character, Negima has two female leads and one male lead, Mahou is all female leads, and Sensei has a female lead).
Though I guess I should limit my scope a bit since Naruto does the exact same thing and Sakura was one of the main characters for a bit until she sort of became a tag along whos Chakra control and intelligence greater then anyone else somehow made her more useless (I just LOVE the filler episode where a random character actually has to save Sakura from her own ineptitude... in an area SHE is the expert in). So limiting it may be warented.
Heck Yakkate Japan!!! even makes fun of it with the Female lead complaining that in all honesty she SHOULD be the main character yet she has never actually done anything for the entire show (I used to think the show subverted it with one AWSOME female character who used science for great cooking... nope it was just a male with medium flowing purple hair, lush lips, and a female voice).
-What is interesting is it is true. She actually has more investment into the series and storywise is supposed to have as much skill and knowledge as the other main characters including a specialty in French baking. She is thrown to the wayside.
Ultimately it seems like... if a show doesn't have a female focus they will probably die, become useless, or sort of phase out.
"There's plenty of badass plot women"
Hey I am not going to argue there arn't badass plot women. Heck almost every series I watched had one. The real measure is if they stay that way (sometimes they get a buff, but it never lasts). It is almost like being a woman is somehow a gimic and is only there to meet some sort of quota and move on.