It is not necessary to agree with someones lifestyle or points of view in order to respect them. That's part of living in a diverse society.
I don't believe that "identifying" as something other than what I am will magically change what I am. However, there are people that do identify as something other than what they were born as.
If someone wants to live a certain way or believe in certain things, and it doesn't affect anyone else, then who cares?
Everything carries risks, and yes there may be people who would use this as an opportunity to commit crimes, but that's not a valid reason to deny a marginalised group within society something that can make them less marginalised. Tackling crime and promoting equality are two separate matters entirely.