Ohhh what a wonderful review!
Difficulty wise it's a great game but oh boy will you hate it during some fights but! You're right that Reborn is pretty much never unfair because there's always a way.
Huge piece of advice is to train more than six Pokemon, not necessary at the beginning but you'll thank me later on lmao.
Also in the Grand Hall there are a few repeatable trainers (they depend on the day of the week), grinding is still tedious as always but it makes it easier haha.
I hope you'll enjoy Reborn as much as I, and many many others, did~