Hello, while I agree EXP can be hard at the start.
There is many ways to gain EXP such as the copycat you can found in every city with a Gym but doesnt making the Trainer refight possible after 1 day will just make the game easiest ? Fighting over +5 NPC per route can be too much EXP and player will just be over-level.
And -1 for region locked pokemon, it's just to strong and we know what will happens, seing the same pokemon such as Moxie one (Sandile, Gyarados, Bagon etc..)