Just gave it a go. Pretty nice! I ran into the key issue as well with CQ3.wad as my iwad, but it works fine as the iwad.
I liked the redone E2M1, though the lift needs some sort of gate when it is up, otherwise I feel like I may accidentally walk under it and get crushed, only to find I'm walking against nothing. Felt kinda strange.
I loved the slopes in E1M5. Really felt like a cavern, more so than the original.
I agree with what you said elsewhere, about replacing residential stuff on the ground level of E2M4 with shops and offices. It feels really plain, especially with the way you've redone the other maps. Maybe replace the streetside sewage mains with store lobbies or something?
Also, I noticed that sometimes the fruit bowels seems to have thicker black outlines. I noticed this on E2M2 and E1M4 in the mazes.
All in all, a nice jaunt for this evening. Well done so far!