Common event leveling system troubles

For my game I was making a custom leveling system that will allow flexibility on the players stats and the rest of their party's stats. So I figured I would have it run as a common event in the background. However I didn't realize until testing it that every time you enter into a room it restarts the common event from the beginning. Is there any way to prevent this from happening so it just continues running or if there is a way to accommodate for this I would like to know any suggestions.

A snippet of the code is attached. It the entire code will follow this pattern (if it can be fixed)

This is spaghetti code. I strongly suggest to use conditional branches than Label jumps.

Anyway, to your question:
Map events run on map load every time. That is natural.
A workaround is to use switches, to decide whether it will run or not (conditioning the event pages you can make it run a blank page).

Interesting approach but id rather use a manual level up/stat distribution plugin than do it on an always running item-based event.

IF you decide to keep the event thing running my suggestion is then make 2 or more common events.

A main level checker event where it checks and stores character lv as a variable, and then checks for changes on that (current level > previous stored variable) and when that changes due to level up.
Then you run the long script. Better yet, separate each character script on its own common event and let the main "level checker" event decide which one to run, this will give you individual shorter codes. Also please use branching (When/Else), labels are better suited for looping scripts.

Why the suggestion on going the manual level up plugin route? Assuming you're doing a multiple character party and everyone gets these stat up items, what stops me from using all the stat gain items on one character? Are you going to make separate version of these items that only work on a specified character? What happens if i hog all the MP up items to dump on the healer?