I've never played the games, but I think you might be throwing too many logistics into it, which is going to make it rather impossible to keep track of.
The only points you listed which are worth implementing, in my mind, are:
- Inventory (relatively simple, as long as you limit the number of items and not go OTT).
- Quests (Obviously needed to keep them all busy! Since you've played one of the games you could always rehash quests from that, since I assume the main purpose would be the standard 'go here/protect him/slay this' kind of quests).
Passing out could instead be controlled by a structured day/night system. If plays have to pass out and go back to a campsite it could severely halt the progress of the whole group.
Equipment isn't necessary in RPs, except for aesthetic and description. There is no use having literal stats, although special received items could easily have descriptions such as 'increases your characters speed', which can then be written in by the player.
Damage/Boss Battles is again nothing too special to RP. Consider we manage this all the time in Pokémon RPs. Simply set some kind of standard, let players leave their posts on what they think is a 'finishing' move, then tell them (in OOC or IC) if the attack was successful/general outcome.
Errr I think that's all I can give in terms of ideas, unless I quickly read up on the mechanics of Monster Hunter - but yeah, I think you should try and separate the idea from the rigid mechanics of a game.
You have to play Monster Hunter to really understand the whole concept.
Inventory could be monitored by individual players, but there is also "If I dig in this bush, what will I find?" more than one type of item can be picked up in gathering spots. And quite frankly, literally half of the game is item gathering/combining/using, making potions and cooking meat, making traps to subdue large monsters, making pickaxes or fishing bait, using bugnets, the list goes on and on. There is a money aspect to the game, but it's far, far more wise to go by item combining, and gathering. Other items, like monster carves and boss monster carves, go into the creation of specific weapons and gear.
The Items and Equipment make up most of the entire game, and it's one of the most fun things about it. With armor there's good ol' defense, but then you can also have resistance (or weakness) to water, electricity, fire, dragon, etc. based on your armor, which is also based off of what you made it out of. Both armor and weapons can have special traits. With weapons, there's different levels of sharpness, durability, strength, and other special traits like auto-guard. Weapon types (DualSwords, Sword'n'Shield, Longsword, Greatsword, Lance, Gunlance, Hammer, HuntingHorn, Bow, Light Bowgun, Heavy Bowgun) determine other abilities, special moves, etc. Bows and Bowguns have different ammunition types with different levels of strength, have reload speeds and recoils, different clip sizes, some only use certain types of ammo... My point is, taking out that aspect of the game is pretty much taking out the game.
You could go off of roleplaying realism, but do realize that, game-wise, these bosses can last from anywhere between 10 minutes and 50 minutes of game-time. You have to come prepared, with the right types of weapons, the right items, and the right armor, or you'll fail. It's not easy.
What I mean by passing out is basically "Dying". With an average quest, you get three "lives". If you run out of Health, your character becomes unconscious and a ragtag group of Felynes takes you back to your campsite on a stretcher. If you pass out, you lose a portion of the reward, but if you fail three times, you're forced to return home and fail the quest.
Someone who's played it probably would have to be the one to GM it.