To the detransitioning thing- yes, valid, because gender is a whack thing that changes over time. We know virtually nothing about the root causes of dysphoria. It happens, no one's in the right or wrong because of it.
To the LGBTQ affirming Christian thing- To start, I am what most would call a "strict" Christian. I believe the Bible is the Word of God, I believe God loves all people even though we're sinners. And that while we were sinners Christ died for us, defeating sin and death, then rose from the dead proving it. I believe Jesus was/is the Son of God but also is God incarnate. I believe the only way to "get to" heaven is by acknowledging you're a sinner and accept Jesus as your savior, and through that, form a relationship with God. I believe the greatest commandments are to love God with all you have and to love others as you love yourself. I believe God's kingdom is open to all people. I'm pro-life, and believe sex should be reserved for marriage (though I can't judge people who don't align with those beliefs). Those parts of my faith will never change. Recently I've looked into LGBTQ matters in relation to God. I'm curious as to whether or not LGBTQ people are really sinning in God's eyes when they're in loving, commited, monogamous partnerships. I've listened to both sides of the debate, from both philosophical and scriptural perspectives. I've studied the Greek and Hebrew. I've picked apart the few passages that do mention homosexuality. I've watched hours long debates and panels. I've seen interviews of very orthodox Christians who argue that their orthodoxy affirms LGBTQ people and their relationships. I've read entire websites. I've watched LGBTQ people with masters degrees in biblical theology speak on the matter. I've heard the counter arguments to the counter arguments. Quite frankly, I'm obsessed. I've read whole websites and watched way to many videos.
And you know what? I haven't come to a conclusion. Not yet, at least. I'm not finished with my research. Regardless, God loves all people- that's for certain- and you can be a Christian and be queer affirming. I'm currently leaning towards the more affirming side. Politically, I'm definitely an ally. Personally, I'm queer. It's hard to discern, but I pray God leads me on this journey and reveals something to me.