That is a popular fan interpretation of Jadzia. I can see some similarities, but I don't think the Trill are even as much as an allegory for transsexuality. That interpretation is very reductive and dismissive of the transsexual experience.
A gay interspecies couple
Garak and Bashir were originally portrayed with gay subtext. Producers put a stop to that before anything actually developed between the two characters.
People in my organization do this, and it's great. The only downside to that is when you want recipients to know exactly who else the email was sent to. Not super common, in my experience, but it does occur.
In TOS, there were more characters in red shirts than any other color. So of course most deaths were characters wearing a red shirt. Proportionally, I believe it was actually yellow with the highest mortality rate.
Feel free to actually do something with all these. I have no ideas.