Out of curiosity, have you played any FE before awakening? Because i disagree.
I dislike the class changing and skill inheritance of awakening and Fates, wich i consider a humongous grind, wich the older games didn't have particularly because who they were and their class made them fit as part of the world and didn't force you to grind with multiple units to get the "perfect" setup. It forced you to build strategies with the resources you had. Also, little to no backtracking was a staple of the series i wish to see back, because FE used to be a story driven fest and not a grind and breeding fest. It completely ruins the pace.
Pair up was never very cool to me and just exacerbated one shot situations.
I'm surprised that there is no triangle. That is very weird. But overall you got me interested in Echoes. If it's not doing what Awakening and Fates are doing, it can only be better. Just the "dungeons" part didn't resonate with me.
Its a remake of a game before the triangles and yes, I have to agree with what you said about the class changing and inheritance. I don't like it, I never have. Pair ups I'm fine with but the majority of his complaints are old mechanics and quite frankly I enjoyed echoes FAAAAAAAAAAR more than I did with awakening. Its the FE that I like. It has its quirks but I quite enjoy it