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Hmm, I should make my next post an #introduceyourself - was planning on my next post (which is gonna sorta be the first in the new theme properly speaking) being a sort of quick FAQ about gender dysphoria and a stripped down life story discussing how I finally found myself.

Think it'd be appropriate to do all that in an #introduceyourself post?

I'm not a good creator so probably I can't give best advice here. Introduction is for the first appearance so a good starter for series about yourself.
That tag is good for personal story, I'm not sure if it's good for FAQ (might be too long, too boring)

For example I don't care about LGBT topics at all, I'm looking for a good content, such as interesting story. Yours sounds promising. Then I guess I will have questions that I'd like to find answers for, some of them for sure are from "Frequently Asked" cathegory.
Where to put that?
I don't know.
Current UIs doesn't really have anything but simple user profiles.

Separate post that you could reference to later on?
Monetization is limited to 7 days, but editing old posts is unlimited.

https://steemit.com/introducemyself/@garethnelsonuk/introducing-a-gwen

I kinda messed up here by posting in #introduceyourself by mistake, is it worth reposting in the correct category you think?

Anyway, there it is - i'll probably leave it to be honest, i'll start writing up my story post too.

It's ok. Having #introduceyourself as one of the tags is enough.