I'm not denying anything. Having an advantage does not mean you should be disqualified from competing. You mention "bone density, muscle structure, frame, strength." What professional athlete does not have biological differences when it comes to these things? Serena Williams isn't Serena Williams because she worked harder than all the other women. She's Serena Williams because she was born stronger, bigger, wider, quicker than my sister.
And we have to consider the outcome. You come up with a handful of trans women competing(with one of your examples being 15 years old, which is downright ludicrous), but what was the outcome here? Who exactly is with unfair against? How many WNBA players are trans? How many NWSL players? How many of the top 100 players on the WTA tour? How many of the medal winners in track and field or swimming at the Olympics in Rio? You keep talking about a slippery slope, well, where is it? Where are these trans women who are dominating world class sports competitions?
And hell, even if you had a point, if a G-League player is willing to cut off his penis and undergo hormone therapy and put up with everything else that comes with transitioning, in order to possibly make 30-40 grand a year more, by all means, they should. If they're willing to do all that and can still dominate the WNBA, I tip my hat to them.
I don't know about all of that. The difference in strength between men and women is huge. It's a pretty insurmountable advantage, and it'd be extremely unfair to the other competitors.