Ezit Meti said:
*sigh*
It seems to me that this point is most commonly used with people that intensely dislike the Ranma/Akane pairing. That the only reason that ship has the remotest chance to sail, essentially, is that Takahashi was going out of her way to protect her own favourite couple. Which included protecting her own author avatar Akane Tendo.
I personally find this manner of argument more telling about those that would make it rather than Takahashi. But to address the question actually asked.
It would tell us that she has a strangely, outright peculiarly nuanced outlook of herself as a person. She views herself as pretty, maybe kinda cute but not quite as hot as some of the other women around herself. She also views herself as a generally kind an considerate person, but with a pretty wicked temper that is combined with a bit of a stubborn and blinkered viewpoint on the real world. She's lousy at feminine things, can't cook or sew and I don't think Akane's all that great at drawing either.
That's a pretty remarkable view to have on yourself as a person. Like pretty much the rest of the cast, Akane has a bunch of positive traits that are heavily outweighed by the negative. Which makes sense when you consider that negative traits lead to comedic confrontation at an easier pace.
Maybe, just maybe, Akane isn't intended as an author expy? Maybe she was a character that developed largely out of what the series needed to advance right there and then. Which is what I'll believe right up until I see evidence to the contrary.
That's actually kind of a fanon view of Akane.
She's really Shinobu 2.0, especially in the manga where her suspicions and irritation with Ranma and others are generally justified. She also overreacts a lot less, especially in context with the other characters and the situations she finds herself in. Ranma is shady and not trustworthy in the manga, and actively manipulative pretty regularly, so even when she is distrustful of him when he's being on the level, she has pretty good reason to be suspicious of him. In the anime, everyone got dumber to play up the slapstick and comedy elements, especially Ranma. Akane really isn't any meaner in the Anime, she's just more oblivious, dumber, and jumps to conclusions to play up and exaggerate the comedy elements more.
That said, she is a proto-tsundere and a violent bitch. She's just not as bad as a lot of people seem to imply, especially in comparison to pretty much everyone else in the show. She fits in with the cast overall and isn't really worse than any other female character if you look at them all objectively. It's just fanboy favoritism that elevates other cast members over anyone else really. They're all basically careless thugs with little regard for others and mostly selfish personalities. It's just slight variations on that depending on who in particular you're talking about. Urusei Yatsura ran on the same gag that everyone was equally horrible for different reasons and Ranma continues that trend. Takahashi has a pretty dark sense of humor really, and the whimsy of it kind of hides just how awful everyone really is.
I'm also pretty sure that Takahashi has said that both Akane and Shinobu [Kagome, Kyoko, etc...] were the characters she most related to and were her perspective on the story, but not that they were self insertion characters either. Akane was the character she viewed the story through, but she wasn't really supposed to be a direct representation of Takahashi either. It's not really an indication of Takahashi's self image at all I don't think. It might provide some insight to how her mind works in an abstract way, but Akane is not a SI character, she's an author proxy, which is not the same thing.
She intended to write Urusei Yatsura with Shinobu as a proxy to begin with, but then Lum became the focus because of the fans and her publisher and Shinobu got shoved aside. Akane is the same, she's a proxy, not Takahashi's literal self projection as a manga character. She's just the character she most relates to and represents her viewpoint on the rest of the story, even though she's not really the main character.
I couldn't find anything to back this up, but I believe she has answered this in SS interviews or promotional materials at some point in the past while the series was still running.
I think the issue here is that people are confusing an author proxy with an author self insertion character. In a lot of fiction the author has a proxy character whose perspective they mostly follow to tell the story, but that character is not necessarily similar to the author's personality or appearance or intended to be anything like them at all. Often it's the main character, but sometimes not. This is what Takahashi tried and failed to do with Shinobu due to fan and publisher pressure, and what Akane is in Ranma 1/2.
I do this a lot when I write actually. Most of my "SI" characters have elements of myself in them, but they are really actually proxy characters and not true representations of myself. Most of them do things and make decisions I just plain wouldn't. There's more of me in some of them than others, but none of them were ever really intended to be 'me in this story', but rather my proxy through which the story is mostly told through in my head. The guy whose perspective I see the story in my minds eye through, and yes, it is often, but not always, the guy who has the most 'me' in them out of pretty much everyone else.
Early on when I first started writing I actually did start out trying to write myself into stories, but it never lasted long, but the characters quickly evolved as the gags or situations kind of pushed the characters out of that zone and into being their own thing, after a while I stopped trying and just started out with a proxy that only kind of vaguely represented myself in a very loose fashion, but really not.
That's also not absolute. There are plenty of scenes and even segments in some of what I've written where I disassociate with those characters and see things from a different perspective for various reasons. I think that's pretty common actually. Akane is usually the character Takahashi had the closest connection with and her perspective was who she experienced the story through herself, at least through most of when she was writing the manga.
TL;DR: A lot of the "Akane is Takahashi's SI" talk comes from those who don't get the difference between a SI author avatar and an author proxy character.