Re: Valentin (with transgender intent)
I'm not sure I follow your reasoning: you are transitioning to male but keeping Amelie as your first name? Wouldn't it make more sense to select an A- name, perhaps Arthur or Adrien, or even just Adrian, and by all means go by your nice new mn but keep gender consistency? I don't enjoy Valentin(e) at all, but that's because of February 14 more than the name itself. Romantic, perhaps, but mostly just commercialised.
I'm sorry that you find it necessary to pre-empt people's possible hostile reactions to your situation. I have never seen evidence of homophobia, transphobia or whatever on these boards, and I don't expect to. You might consider waiting for something to react to, and then express your perfectly justifiable displeasure, rather than jumping the gun.