Much like the changes I've heard about in VIIR, I'm willing to forgive some things (Mikoto revealed to have the Echo - while this was never stated in Return to Ivalice as a Student of Baldesion I suppose it makes sense), others less so (her Echo lets her see the future rather than the past). Dates don't bother me, but playing hard and fast with the rules of the setting is something I very much disagree with.
Midas being tempered isn't a huge shock; it was implied way back when. This just makes it explicit.
Surprise trial is against a memory of Varis back during his days as High Legatus. EX only. Whoo.
No grind part to keep people occupied until VIIR hits internationally. Ahh, how... disappointing? Relieving? Not sure.