Thinking back on this topic, it occurs to me that EXP data is not kept in the data folders, and instead is stored in the actual EXE of the game itself. So, that would require some additional additions of some kind. Upgradable weapons sound kind of cool, though with randomized EXP it would be either more of a blessing or a curse type of scenario, where you have no idea whether you can level up the weapon quickly, or if it will take forever, making life a lot harder.
Also: randomized booster v0.8 and v2.0 locations would be cool, except that would mean you'd have to remove all of the flags that connect to things like: the bad ending, whether or not you get into the v2.0 version of the last cave, or so Booster doesn't die meaning that Booster appears in the teleporter possibly giving another randomized item, and so on and so forth. Basically any point in the game where it checks for either one of the boosters, or a flag that was activated upon collecting the booster v0.8.