Oh hey, cool, thanks for the advice 
I use game instances because they’re really the only way I know to have persistent data, and the only thing I know of that can interact with any other blueprint. Unfortunately, and I have no doubt this was a bad idea (seemed good at the time, though :P), I don’t really have a specific player character. Instead I have the actor I want to be controlled spawned every time a level loads. At the time this seemed like the most flexible way of doing things, if I wanted to have multiple PCs etc. Actually, now I think about it, this might not be such a big deal; I’m doing the old-school JRPG thing of having random battles that take place in a separate ‘arena’, so when the player’s moving about in the world their stats don’t matter. Hmm, but they do have to be able to access their inventory…
I think, ideally, I want to have several separate places to consolidate all the variables that would be necessary, eg an inventory, character stats, variables used in levels, variables used in battles, etc. Is there a way to create these separate sets of data in a place that can be accessed by any other blueprint at any time?
Regarding the experience system, I have enough knowledge to implement something like that without too many problems. My issue is more with figuring out where to store that data and how to make it as easily accessible as possible to all other blueprints/actors/whatever.
Anyway, I’m not sure how much sense I’m making, but thanks again