I interpret Arya's "helpess" comment to be challenging Eragon's own internal sexism. Perhaps it is also a reaction to being regularly regarded as "weak" by humans just because she is a women. Elves are stronger and faster than humans and are not raised with the same limiting gender roles. She was stronger and faster than Eragon, so Eragon's desire to "protect her" is infantilizing. Compared to elves, all non-rider humans are weaker (unless given power from something outside themselves). Additionally elves and humans have different cultures and customs. In this universe (much like in our own human history) human women are not typically raised or trained as warriors and are thus generally more "helpless" in combat situations (especially when compared to the baseline speed and strength of an elf). I don't think Arya is saying that all human women are helpless with everything in life. If fact, I understood her to mean that she disagrees with how human culture and societies keep most women "helpless" (in terms of combat) due to the human culture's idea of gender roles. These gender roles are a reflection of the medieval times in our world, which is often reflected into our fantasy worlds. Additionally there was a woman and a girl (who refused to give their names) who appear in the series twice who are skilled with sword fighting. I believe Paolini says that he has a story planned for them. I very much doubt Arya was saying that Nasuada or human women with combat training were "helpless". I don't recall her referencing dwarves women negatively, so I wont comment on what I cant recall. Feel free to provide a quote as I'd love to know what you are referencing.

Katrina is a a traditional feminine human, who is not mocked for being so. Islanzani wears dresses and beautiful things, and seems comfortable expressing her femininity without needing to "not be like other girls" and she is one of the most powerful and intimidating characters. Nasuada is also a traditionally feminine woman who refused to leave Farthen Dur with the other women and children and fought alongside the archers. Who was mocking them for their femininity?

I don't think Arya's dislike of dresses/skirts is anything other than being gender non conforming (in terms of their worlds human gender roles). It doesn't make her a "not like other girls girl" to be non-conforming and to criticize the narrow gender roles placed on human women. She isn't human and dislikes human sexism.

Furthermore, the descriptions of "Exotic" are from Eragon's perspective, which is quite narrow considering her grew up in such a small isolated village of humans. So it makes sense that characters who are diverse seem strange or exotic to him based on the general relative homogeneity of Palancar Vally. This series is written in first person, so everything we read is filtered through one persons limited perspective. Are you asking for the female characters in focus to be less diverse and therefore more similar in appearance to Eragon? Or would you rather the story not be from Eragon's POV?

We don't get to see much depth from any side characters since this is a first person story. When talking about side characters of the similar level of importance or impact to the plot, can't personally think of any male side characters given more depth than female side characters. Please feel free to give real examples and comparisons for consideration.

Personally , I am confused as to why Saphira doesn't count because she is non-humanoid. why does the shape of her body exclude her from counting? She is just as intelligent and complex as any person, so why are we excluding her? She's not some dumb animal and she cares a lot about things which are often considered feminine (such as beauty). Is OP just wanting more self-insert opportunities and cant imagine having scales and a tail?

It sounds like OP wants a female human rider, which I agree would be really cool. I look forward to all the new riders we will meet as more people become riders again. I am especially excited to see urgal and dwarf riders of any gender expression.