>>724998719
Few RE5 mechanics translate to 6 and the partner is immortal there, so don't worry.
You did a pretty awkward thing picking veteran first, the game is built with the upgrade system in mind and enemies are more aggressive on veteran so you got a pretty rude awakening.

>Hated the inventory system, but I understand that it was necessary not to pause the game since it's supposed to be a co-op game
It's annoying at first, but it suits the gameplay pretty well once you learn how to properly use it. Keep weapons and grenades on the quickslot squares, ammo next to guns so you can instant reload and dont be greedy. Those nine squares fit two weapons, two packs of ammo, two types of grenades, two heals and a vest. It's more than enough for the whole game.
>A truckload of enemies on almost every area and many of them were huge damage sponges
The damage is mostly due to you starting on veteran. Regardless, you can run past most fights in the game. The lickers indeed are a huge pain, the best idea is saving the grenade launcher just for them. The only chainsaw majini you need to kill is the first, the others are optional.
>Boss fights sucked ass, period
True, they are pretty lackluster. Did you enjoy the Wesker boss though?
>Pretty much stuck with early-game weapons because everything else came too late.
All weapons are usable so it doesnt matter much. The game expects you to try other weapons on different playthroughs.

A tip if you ever replay it. Give the AI partner different weapon types than yours so you dont share ammo. I reccomend an smg and a sniper, as the ai never misses and doesnt go for headshots. Also change it's behavior on the fly depending on the situation. The ai on attack mode is a beast, if you can babysit it well enough.