After receiving another round of feedback, I've decided to take the time to go back and polish up the first several levels of this wad. It feels like a good time to do so after getting through level 10. It's still ongoing, but I've got a couple of points to share:
1. I don't think I'll be converting this to Boom compatibility or to UDMF, at least any time soon, after looking into those options. It doesn't look the way I want it to in the Boom copy I re-textured, and UDMF is a bit too much of a stretch to redo 10 levels with. (If anyone has any advice on compatibility, I am open to listening, as it's an area I still need more knowledge of.)
2. Map02 is mostly undergoing texture alignment, with some more detailing added in. I've also decided to remove 2 of the 3 Hell Knights from the red key room initially, and have them come in as an ambush after you grab it, to make this less of a slog.
3. Map03 is getting a new area, that will get you armed with a non-secret super shotgun. It's also getting one rather nasty Arch-Vile because I thought it was a crime that this map used the track, Message for the Arch-Vile without having the titular baddy. Again, Textures are being fixed to look more appealing, with more attention on alignment this time around. The Exit Door will also be made double-wide to give the enemies more space to come out.
4. Map05 is getting a bit of a rehaul, texture-wise, as well as the lost soul hallway, is getting a bit of a rework into something with more space.
5. On Map06, I finally found a way to make the glass mid textures disappear after grabbing the red key! I was pretty happy about this one, and it involves some geometry tricks. The result also gave me ideas for the future, seeing as you can actually watch the glass (Or any mid texture) go up. Which, as far as I know outside of this geometry trick, mid textures are usually removed with scripts. This idea is kind of an expansion of what was done in Plutonia's Cyberden, involving a few extra steps.
6. Map08 will be getting a new secret involving water, as well as a rebalancing of the room behind the yellow door, to have a little less infighting.
7. Map09 will have a few 64 wide doorways increased to 128 wide to reduce amounts of Door Combat, and the Mancubus now walk all the way over, instead of having a monster block line. It should take them a while to join the fight, but they won't be awkwardly blocked anymore.
8. Map10 needs a fair amount of texture work done on it, otherwise, I'm happy with the gameplay of it.
I'd like to continue to improve this wad, and as such, any feedback is appreciated, even if only in text form! Thanks again to all who have checked this out!