Re: Your first block. I didn’t recall there being a request for a concession, but that doesnt’ help your argument. If the Night Elves are part of the Alliance, but do not gain its benefits without people demanding a pound of flesh, that’s a reason to not be in the Alliance.
Re: Your second block. They do not contradict. There are Night Elf NPCs in the Alliance forces under Admiral Taylor. We’re not talking about adventurers being sent, we’re talking about direct forces.
Re: Your third block - If we go by actions? That is how it appears - at least where Stormwind is concerned, and it’s concerning that they again wanted to build what could be used as a logistical dagger to the belly.
Re: four - Read what Tyrande says again. Varian believes that giving up Azshara would be helpful for peace, Tyrande is reluctant, but relents. She’s skeptical that it would even work, and given Teldrassil, she was right on the money.
Re: Five - they were getting killed by Deathwing - he specifically targeted the zone in which they were housed.
Re: Six - It was a choice between the “safe” option and the “risky” one. The “safe” option was based on the idea that the Horde wouldn’t raze the tree, which again reflects Anduin’s failure to judge his opponents. This again is something to be noted when he asserts that he believes that the Horde has changed. Changed from what exactly? We don’t know - he never knew them in the first place.
Past that, even a tiny addition of forces given the situation, given how to-the-wire it was for the Horde had the potential to change the entire situation. The WoT was winnable, but the Alliance threw that chance away in the earliest moments of the fight.
Re: Seven - It’s really notable how the EK is prioritized, but the Night Elves are asked to deprive themselves of their territorial defense for the sake of pursuing Stormwind’s geopolitical objectives. This isn’t an argument in favor of the Night Elves continuing to be involved in the Alliance. It’s a statement that the rest of the Alliance sees the lives of their people as secondary concerns.
Leading me into 8:
Ah yes, patience to watch the Humans carefully secure all of their geopolitical objectives while not caring about the Night Elves’ core territories. Stormwind did not need Lordaeron to be secure. It didn’t need the Arathi Highlands either - the land bottleneck could have been established at the Thandol Span much more easily. These were wants and not needs for Stormwind, and despite that, the Night Elves went along with them before being presented with this naked power move that Anduin wanted to pull over fulfilling his commitments to his allies.
The Kaldorei were being taken advantage of, realized that, and bailed - and they were right to do so.
Re: 9 - Again, if your argument is “Stormwind can’t help the Night Elves in their time of need”, then that’s not an argument for the Night Elves to remain in the Alliance. It’s like signing up for a wine club that can’t physically ship you the wine, better to save your money. Or in this case, and leading to 10…
Better to not send your troops to secure something that Stormwind is concerned about, thereby leaving yourself open for the Horde to use a mass death event rendered on your people as a means of getting at Anduin. A Good War demonstrates just how difficult it was going to be for the Horde to do what they did - and given the terrain advantages that the Night Elves enjoy - that makes sense. They were only able to do what they were going to do because the Night Elf military was pulled away to deal with something that Anduin was worried about. I again don’t absolve Tyrande for her role in this decision, but without that decision, there would have been no Teldrassil, and Sylvanas would have been forced to look for some other way to get at Stormwind. The Night Elves were made to sacrifice their whole country for the Alliance, and the Alliance did not reciprocate because Stormwind was busy trying to secure its own geopolitical wants. That is a clear case for an exit.