1. i think johtos level curve is intentional, you are supposed to be underleveled in gen 1 & 2. badge boosts do most of the heavy lifting for you, its more of a hgss problem, which still isnt that bad when you remember pokemon is a baby game and you can just do as the ai does and spam full restores/max revives and be fine killing red at like level 55. im sorry that you have autism and have to do a nuzlockerino. johtos real problem is kanto, which was fixed a bit in hgss but id much rather live in the "fleshed out johto" world than the BRO YOU CAN GO TO LIKE 7 REGINS JUST LIEK ASH BRO and every region after the first one boils down to a mindless 3 hour boss rush
2. i think hoenns problem is less that there shouldnt be water routes and more that there should be more of a point to them, and more ocean themed pokemon (that dear god arent water type)
3. sinnoh does need more fire types but i think it needs more things in general to set it apart from hoenn, of all the gens in the series it feels the most like a retread (even more than the literal retread region (johto))
4. no complaints with unova, dream world definitely bogs it down and steals features from the real game, id just gut the c-gear entirely too and give it hgss's bottom screen (perfection)
5. id replace kalos's fix with just a picture of the letter z