Hey @Stellarbe
“-For me”, it’s only 4 very silly things.
like described:
number 1 - Very…very good “- icons and textures…” :
Use simple color placeholders 
number 2 - “- Tutorial blueprint / helper text renders not included.” :
It’s not complicated. I think in less than 15 minutes you can do something very acceptable. (small blueprinted tutorial containing links referring to manual, site, forum, etc). I’ve seen in many assets, things like a link to forum thread only. Nothing else. Maybe it’s a dead fly on the soup trying to discourage you
number 3 “- Incorrect/Inconsistent naming conventions.”
What? That’s it only!:“A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums”).
number 4 “- Does not follow marketplace guidelines” : Very ambiguous redundancy. Maybe a condensation of the same things described (number 1 / number 2 ; number 3 ; and again number 4… closing an infinite loop)
And even after you have followed the steps above, It can be: 1- something personal with your own person. I doubt this: they can not have nothing against you. They do not know you). 2 - Really it’s not good thing. I doubt this also, seeing the showcase video. (Seems pretty good RPG framework.) I liked a lot!
I just think you could review these 3 steps and try again.
It is similar to an interrupted telephone call, If the connection hangs off, Call again!
And to finishing the appointments.
So that no one can to say the marketplace is full of the RPG content, which is untruth: Why not innovate future releases adding option for five RPG game “types”. Top-down, isometric, third-person, first-person and VR ready - RPG with VR or AR interaction. Taking advantage of the demand
Please, try submitting it again.