I'm so glad you enjoy it!
Regarding the doors, I actually brought the power consumption of the doors down a little bit for this version because I thought previously the power drained too fast. I guess not! Next update will for sure fix that lol. That's also interesting because when I was doing some play-testing recently, I've noticed that Mia the Monster is able to either, a) basically phase through the right door, or b) is really good at sneaking in at the last second. But since you mentioned how much of the game you can basically skip by keeping the doors shut, it's good to know that she may not be quite as broken as I thought. Still, I'll fix that, too.
Since I've actually tested this game a fair amount on original hardware on a CRT, I can firmly attest that yes, a CRT is totally the way to go with this game if you want the full experience. Like you mentioned, the flickering is barely (if not much less) noticeable, and there are also some subtle effects and events that are especially effective that way (i.e. the death screen).
Still wondering if there's any way to reduce the screen "shakiness" in the NTSC/PAL60 versions of the game (unavoidable regardless of what you're playing on).