Well sure, but that's not the point here.
You can define the words you use as you want, but you won't change the fact that people will get them in the way they are used to. Langage is made for sharing. If you are imprecise, you fail at sharing. That's all there is to it.
Transexuality is based on two parts, "trans" and "sexuality". That's not a question here. There's no "uality" added at the end. It's sexuality we're talking about - a word that became, with time, related to sexual behaviour and preferences. I prefer "sexuation" because it's relative to the sex differenciation. It's more precise.
That's also why I don't like the "feminist" term. "Feminist" and "Transexual" are words that are unprecise, but hold an historic meaning which I like and respect. But in the end, langage is about communication, not about history.
Personnally, I have no problem with the transexual term. It has a bad connotation but well, it's not the word that have a bad connotation, but the people that are supposedly define by it. I just think it's a word that doesn't describe me well. That's all there is to it.