Just my thought.

Since doping has been pretty well discussed. Will it hurt the balance of the competition between women? Will more female athletes resort to doping or harder drugs just to keep up with the competition? 

What's your point, OP? That hormones can be considered doping and such the percentage goes up, or that transgender females are better suit for sports than females and that will force the later to undergo doping?

I don't know but I still think it's weird that male-to-female athletes are allowed to compete against naturally born females. It seems to me like they have quite an advantage physically speaking. I guess it's not a problem until a situation arises.

The physical advantage of males is in most sports negligible or even non-existent. You could just mix alot of the sports.

i really doubt this, i wouldn't bet my money on federer or djokovic losing to serena in 5 sets match.

What are you talking about? Care to explain what you mean by "most sports"? And what sports could be mixed? If we look at some sports where athletism isn't the main factor, like shooting, darts or snooker...even in these sports women cannot compete against men at all, so what the hell are you talking about? What obvious thing I'm missing, please tell me.

edit: Equestrian is one of the very few sports where women can compete against men and that's only because the horse plays the most dominant part in the performance and biomechanically the horse works independently.

edit2: There are already rules in many sports how athletes are classified either a male or a female, so this has been already thought out.

Wait, transgender women can compete against natural women? That doesn't sound fair to the women really, it's putting them at a disadvantage in their own competition

Because shooting, darts and snooker are "traditionally male sports". But from footbal to sprinting, the real physical difference isn't that big.

Sprinting isn't a big difference? Not sure if I read that wrong but if so I'll definitely have to disagree. There's just about 1 full second difference in the WR for the 100M sprint.

Hope it's reversed.