@Sladurche
There are literally five biological markers that go to make you female or male sex. Some people don't tick all the boxes for one sex or the other. What gender you are then assigned at birth and brought up as usually depends on what you most closely resemble. No-one is brought up intersex or genderless; even though 2% of the population is neither biologically male or female.
Gender is an entirely social construct- it is whether you fit with society's expectations of what women should be. Most feminists agree that the experience of being brought up as a woman defines how society treats you as a person. Identifying as a woman is because you have been brought up that way. You have expectations and training. Just like you may identify as being British, or middle-class. It's an experience, a way of being.
Some people don't agree with the gender they have been assigned and brought up as. Gender dysmorphia is a very real condition. The only way to help with this condition is transition. The more you "other" trans people and say they aren't women, the more you make them different, the more you shape the way society sees them. It does not help trans people, it just makes them more unsafe.
That's not a "theory" - that's observable, scientific fact.
"Cis" is just a technical term. It's someone whose identity and assignation matches their biological sex. Those who get offended by it are putting their own illogical and unscientific bias towards it.
This is erroneous. People with DSD's are either male or female. They may not fit as neatly into either category as most of us, but they are either male or female.
Gender Dysphoria is very real ; however, affimative care is most certainly NOT the only way to help. In fact, if you leave most dysphoric children alone; which is to say, you don't socially transition them through name changing or pronoun usage, the vast majority of them will outgrow the dysphoria.
I find cis offensive. Its not up to you to say that I shouldn't be offended by sexist nonsense. Behave yourself.
None of the men who have assaulted me over the years ever felt the need to ask for my pronouns or gender identity because they knew I was a woman by looking at me. And I'm not particularly feminine.
Being a woman is not something you have to identify as ; its something you simply are.