1) A lower difficulty for trusts I agree could be implemented, but I personally do not feel it necessary just yet and, should it be implemented, I feel it should remain a simple option for Trusts for those who are struggling, like how "very easy" solo instances work. It should not creep its way into Duty Finder as the increased difficulty of dungeons is very welcome. Dungeons throughout all of Endwalker were so very easy, so much so if you just used TBN as a DRK you could just negate all damage coming your way in every big attack in some dungeons. I don't want to return to that, the damage is much a step in the right direction of making the game less boring. The way the game is going it is lessening the reliance of the orange ground AoEs and placing that burden on telegraphs - the first boss of Alexandria shows you in a moving line what mechanics are happening in what order. You don't need to react; you need to memorize and learn timings. Trying to react to the ground AoEs will definitely not give enough time.
2) This is nothing like Dark Souls or Elden Ring, you can stop what you're doing completely and look at the telegraphs and you can usually take a few hits (unless they're at the exact same time) and still live. The game isn't pushing you to play perfectly, it's getting you to understand that not everything will show as a ground AoE and will rely on telegraphs.
3) It's nowhere near twitch reaction level difficulties if you pay attention to the telegraphs. This design decision was active throughout Endwalker as well, the only change was that they increased the damage they deal so you can't just face tank everything. As for NPC trusts, they react to how well you do a mechanic (usually at least, there are a few exceptions as to when they'll act strange but that's rare) so if you're in the wrong spot so too will the Trust members. If you're truly struggling you could try queueing with players who could give you guidance or advice if you're struggling or are stuck. It is an MMO after all.