(1) No they should not. Even if "transitioning" means social transitioning without hormones or surgery, most of us will humor the person but won't actually believe he or she is the opposite sex. This goes double when "dysphoria" is such a broad diagnosis that it's not possible anymore to say that transitioning will help, even if there are people who really would benefit from it.

(2) Honestly, I don't want their support and genuinely feel bad for them. Many of these people would have probably been gay men or lesbians 50 years ago but tried to suppress that instead.

(3) No, N/A.

(4) Yes. The gay / straight alliance at my university was hijacked by "queer activists" in my junior year and that was enough for me to stop going. Outright shaming of gay men for "first world problems", pronoun silliness, and "gender workshops" were all instituted in place of harmless fun. As a gay man who just wants to be treated decently and otherwise left the fuck alone I felt ostracized and hated by the time I left.

(5) Ten to twenty years at least. If the "T" is dropped it will be because of suits against "informed consent" clinics for negligence or against sex-change surgeons for making impossible promises that the results do not match (the late great r/neovaginadisasters should be grounds to revoke all their medical licenses but that's another rant).

Additional thoughts: The LGBT community completely failed at self-policing in the last ten or so years. Thirty years ago, "trans" meant "someone who genuinely and sincerely tries to live as the opposite sex to the best of his or her ability". Now these people are the small minority compared to teens/20 somethings who just want to be special or impose themselves on the opposite sex (mostly men doing this to women, shocker) without any hard work. This didn't happen overnight, it happened over time and got this far because none of us stood up to these lunatics until it was too late.

(end rant).