Played through some of the new map, though I got stuck due to some door linedefs pointing the wrong way.
I like many of the alterations/additions you made here, though a few technical things need to be addressed for the map to work properly. The main issue: all of the doors out of each of the key fights have the linedefs facing the wrong direction, so the player cannot leave once the door closes behind them. I'm not sure which port you are testing with, but this seems like the sort of thing you'll want to note when you are doing a final playthrough before uploading. I'll attach some pics to show what I'm talking about.
Another technical issue: the fight for the yellow key doesn't seem to function as intended, as none of the monsters teleport in, so it's just you and two cyberdemons. When placing teleport lines, make sure the monsters have enough to room to mostly walk all the way across to the other side; right now, the lines are too close to the wall, so monsters can't cross them properly. You might also want to make sure the monsters in closets get woken up earlier, since I can easily run in and grab the yellow key without shooting.
Regarding the fights themselves, most of it crumbles without much trouble. As you can see in the demo, the first leg up through the red key can be handled taking essentially no damage. I liked your baron placement at the top of the steps after getting the red key. The V-shaped arena is a cool idea, though it's largely a roll of the dice whether you get zapped initially, and once the AV is dead, mopping up the revenants poses little threat (this reminds me of the end of Sunder MAP02). I don't know how the fight for the yellow key goes, since nothing teleported in.
Overall, I think you way overestimated the time needed to play the map, as I was done in less than 15 minutes. Your style of combat certainly caters to the slaughter crowd, though the difficulty is pretty far on the easy end right now. That's fine if you'd like to keep it that way, but if you wanted to explore more difficult fights, there is an audience for that.
A note on testing: which port are you using to test? It can be worth noting what you are testing with so that I can more easily navigate bugs that may arise from differences in behavior between, say, DSDA Doom and GZDoom. Also, be sure to do a full run of your map before uploading to make sure everything works correctly, as that will catch a lot of the sorts of bugs that can stop other people's playthroughs.