Alright man, I'll try and help yea. At the very end of each Chapter as it seems this is when the Game is going to be reading the Players Inventory, you'll need an Event to have things , to be, Checked and then Removed retropectively. So to get to that point, you'll need some Variables. Adding items to the player will be done normally. The items are easy.Weapons and Armor are a bit more tricky. Make A Variable for each, just like you would for the Items (I'll get to that in a bit). Now EVERY single time the player get's a Iron Sword or a Black Bow you need to add a plus 1 to the repsected Variable. So lets say a player opens a Chest, gets a Glowing Sheild. You have to add the Sheild to the player AND a plus 1 to that Glowing Sheild Variable. That is how every Armor and Weapon will have to be done.
Now at the end of the Chapter and with in the Event, you'll need a Variable (as discussed ealier) set equal to each item. This is going to let the game read what Items you have, and how many. Next you need (this is imporant, other wise the game wouldn't know what to give back) to have the very same Variables set equal to them selfs...I know that sounds crazy, but it works. So, Example, have a Potion Variable set equal to how many Potions are possesed by the player. Under that Event Commmand, have the Potion Variable equal to the Potion Varible, which make it two Event Commands (you'll have a total of three for each item, but only two for Weapons and Armor). Ok, so the rest is pie. (I like Pie!) Go to the Change Item menu, click remove and refferance to the Variable of the Item you want to take from. Useing the Example above, Potion (set as the Item), click remove, set the Refferance Variable to Potion. The game will now take the many Potions the Player has in his Inventory AND store how many potions he had at the end of that Chapter.
Weapons are done in the same fashion, just you don't have to deal with the first part, just the change Weapons and the Defense Menus. The reason being is that the game already knows what you have, because you were manualing telling it, by adding those plus ones to those Variables. Again it will remove the Weapons and Armor AND store the number of how many the player had.
When you want to give the stuff back, aslong as you didn't mess with those Variables and their numbers, you pretty much do the EXACT same thing, but instead, of remove, you add them. Also don't do the first part about the
have a Potion Variable set equal to how many Potions are possesed by the player.
I hope I helped. Just if you need me to clear things up or you need somethign else.