Level Bonuses Based on Equipment

I like the idea but I have no comment on how you should balance the game with this hack. For its implementation, you need room on the equip data, which I think is full. If you scap as an example the spell teached by equipment, you could use this byte to have 8 different possible bonuses, e.g. byte value 1 would be 1st bonus, value 6 2nd and 3rd bonuses on same equipment, value FF all 8 bonuses on same equipment, etc.

After it's a matter of checking which equipment the character has when leveling up, it's well documented in bank $C2 and a special function could be hooked there. The details of it could come later once you jump in the water, I'd say for a first ASM hack it's ambitious. There's a bunch of details like would you want the bonuses to stack given a character has the same one on his armor and helmet, stuff like this..

If you want to display those bonuses on the item menu screen, there is little room so I'm not sure how to go with this.

Edit: Another possibility is run the hack with a table of 256 bytes and check the value based on equipped item. You could also this way make it to 2 bytes per equipment (512 bytes) and have 16 possible different bonuses. It's not a big step further than putting this on the equip data and instead of scrapping a feature to implement one, you just add value to the game.