I just found this thread while browsing. A few thoughts:
First, the transwoman thing. The word is commonly used by transgender m2f people - at least here in the USA - to identify themselves. There are two terms - cis and trans. Cis basically means the same, and trans means opposite. So a cis woman is a woman with both female anatomy and female self-identification - they think of them selves as women, and look like and function as women to others. A trans-woman is a person with male physical anatomy, but identifies as a woman - they know they are women inside their own heads, despite what their anatomy happens to be.
Since transwoman is a term invented by transgendered people to label themselves, they feel that it's the appropriate word to use. Those same people
hate the word shemale, which was invented by non-transgendered people, and identifies them as only the objects of male lust - that's us.
Use the word shemale to your typical transitioning m2f and you're liable to get your head ripped off - like calling a black person n!gger - not cool.
Transvestite was actually a technical term, invented by some researcher studying males who dressed up as females. Over the years, though, the word picked up a seedy meaning. The only time you'd see the word used would be when some "transvestite prostitute" was busted. Since transvestites usually hung out in bars on the bad side of town, where people were being mugged, drugs sold, etc. the name developed a bad reputation.
So then, some guys who dress as woman but want acceptance start meeting and talking about how to deal with wives, police etc. They are often middle class, businessmen, married and straight. The name transvestite was kind of poisoned by it's association with illicit sex and the criminal underworld, so they when for the more neutral name crossdresser. It says what they do, but it's not an invented word that people associate with perversion.
So now the crossdressers have the Tiffany Club and other national organizations with local chapters. They're mostly white, middle-class guys with wives, and they go to conventions, on cruises, support groups, all that stuff. These are guys who are trying to convince their wives to be cool with their wearing women's clothes around the house, so they need to convince them that they are totally straight, and sex has nothing to do with it. As a result, they want no part of guys who dress as women to get sexed up. If you go to the crossdressers.com forum, you'll find out that it's ruled with an iron hand. If you start posting about how hot it make you to wear women's clothes, and how you want to hook up, you'll be banned. They have a wives/girllfriends section, so they don't want their wives reading about guys having tranny parties and sucking each other's dicks.
So now, the fetish crossdressers - like me - are probably best called transvestites, because we fit better with the old image of transvestites hanging around dive bars on the waterfront. Crossdressers make a big deal about going to the mall and trying to "pass." I'd be much more interested in going to a hotel room with a couple of trannies and getting nasty.
All of the above is opinion, and does not attempt to speak for everyone everywhere. It does, however, come from experience with the groups mentioned - I'm just passing on what I've heard from others.