Thank you, Trax. You're awesome.
Before having a look at my Save Screen issue again I was thinking about the minor bugs/glitches in the game... Not exactly a bug but I wanted to remove the secret staircases under the Armos statues outside Level 5 & 6 as they are clearly leftovers the developers forgot to remove, (the limitation of one entrance per screen forces them to be just a secondary entrance to the labyrinth, and if you exit the labyrinth after you have entered through the secondary entrance, the walking on stairs animation is absent like when you exit a secret staircase) they don't serve any purpose at all and might only confuse a first-time player.
Anyway, is there a value that terminate them? The way I removed them was to place the secret entrance over the entrance to the labyrinth...
10CB2: 24 0B 1C 22 34 3D 4E Screen
10CB9: E0 B0
40 90 A0 Location of Secret
by changing the bolded values to 70, seems to work fine but I just wanted to be sure my approach doesn't cause any potential issues?
Also, is there a way to fix the "magically disappearing locked door" in Level 1?
A few notes from my last playthrough:
On the 1st Quest, no ghosts comes out of the grave where you get a Heart Container on the 2nd Quest. Similarly on the 2nd quest, no ghosts comes out of the grave where you get the Magical Sword in the 1st Quest. Might confuse a first-time player but is most likely a limitation of the two quest setup.
Objects that share the same palette and gets affected when Link's tunic changes color:
Bow and Arrows
Merchants and Zelda
The heart cursor and the Magical Sword on the File Select Screens share palette (Makes the hilt on the sword white on the Erase Screen)
The game's prologue uses a different brighter palette for Link's skin color which in turn makes all those items that share palette with Link, looking a bit different compared to in-game as well. The reason for the difference is of course the palette used on the overworld - Link would blend with the background otherwise. However, I noticed that the game uses the prologue palette on Link inside Level-3 (1st Quest) and Level-2 (2nd Quest), which in turn makes the items and Pols Voice look different in the latter. Either they forgot to change the palette for these labyrinths or they kept it in order to not make Link blend with the background (sand in boss room). But that didn't stop them elsewhere, there's sand filled rooms in many other labyrinths.
A very minor difference in the Japanese re-release on cartridge is that it has smoother transitions when you enter or exit a cave compared to the FDS and NES versions where the hud (bottom of the subscreen) briefly blinks between transitions.
I don't think I will try to tackle any of these, just random observations of mine.
EDIT: On the 1st Quest you'll enter an unwinnable situation if you enter Ganon's chamber without Silver Arrows (and Rupees). In the 2nd Quest, besides Ganon's room, there's two rooms in Level 4 where you can get stuck if you're out of bombs. And if you do dungeons out of order there's a chance to get stuck in both Level 6 and 7. It's never a big deal as you can always bring up the Save Screen and choose continue to start from the entrance of the dungeon. Old and evil game design or simply developer oversights? Tough question. Ganon's room was clearly deliberate evil design. Those in Level 4 might be oversights but the other ones are hard to tell, I guess the labyrinths are numbered for a reason.