"I think that changing language can change behavior to some extent, but I don't think it changes thinking. And I think a lot of times changing language can be a way of hiding a continuance of behavior that ought to change."
this is interesting, talked to my friend about it last night, at first we both immediately thought 1984 and newspeak, and in case you don't know the idea was to bend the meanings of plenty, truth, ignorance, slavery, freedom to where they mean nothing or refer to a definition beneficial to the government. she posited that yes not knowing a term for freedom or gay or trans could lead one to not be capable of conceiving of it. I disagree however, imagine you are in a cage, you will still have a desire to get out and be free, regardless of knowing the word freedom. that does affect your ability to communicate those ideas or about them with others.
she mentioned how not having a word for something like gay or transgender could indicate a non accepting environment or potentially cause one of these people to not be able to "solidify their identity" or "adjust or come to terms with themselves". I disagree with a few of these notions, there would be no adjusting or coming to terms in a truly accepting environment, it would just be another mundane activity or another thing that someone does to groom or decorate themselves.
in fact, I would bet that having words for these things significantly contributes these particular things to being a part of someones identity more so than any random thing they would like to do and do. or maybe the chicken came before the egg.
if one applies the same principle to race it honestly looks kind of ridiculous. "we should continue to have racial categories because that helps racial minorities to accept themselves for who they are". well that doesn't make any fucking sense, and kinda sounds racist. I would argue the categories of race and gender (as the role or behaviors you are expected to show) do a lot more harm than good even if those statements were true. it also shows how those categories have been reified by language. as dot said on a question I asked long ago, we could have just as easily grouped ourselves on something like hair color or eye color.
as for changing behavior in the long run, I do believe that over time continuing gendered pronouns but using them as people ask you to, will lead to an erosion in the importance of gender but perpetuates the idea that certain behaviors "add up" to being this or that identifying group. for that we would need totally gender neutral language which is a huge can of worms for any language other than English as ingrate mentioned. I also think it would take generations for reasons ingrate mentioned, but I do think that language would be the first step towards a world in which when a black and white person approach each other, they don't view that as being an important distinction, just like if another person has different eye colors they aren't a different "group". one could argue that cultural differences can be significant between races but I think this is actually a result of segregation be it enforced or not, not talking about a specific example, any of them. in fact, seeing behavioral, dress, taste in music, or food, as being things that add up to being a certain racial category isn't that far off from a group of expressions or physical characteristics making you a man or woman.
I'm not saying we should never talk about race, but when we do maybe work how we got here into the discussion and solution, instead of solutions that reinforce and perpetuate these categories.
with the romance languages, the perceived masculinity or femininity of the objects actually seems to not be so important always, example: dress in Spanish is vestidO, with an o, so actually calling them nouns that end in a, nouns that end in o, and irregular nouns, would take away the arbitrary assignment of gender to the sounds aahh and Oh. will I still think of it as masculine and feminine for the rest of my life? probably, but If I teach a young child using that language and that is all they are exposed to, I think they would find the assignment of gender quite ridiculous if introduced later on. actually you can see that in English speakers who know nothing of Spanish, when they hear nouns are all masculine or feminine, even pens and pencils, they are shocked and think its weird.