BS Zelda comes close to what I'm wanting, but still falls short on a number of points: Most notably, it isn't available for the GBA, which is my primary target.
Given this, I'll focus the rest of my post on the GBA.
Basically, I hope for a LoZ1 remake on the GBA or SNES which adds the following features:
-Improved graphics
-Save anytime (LoZ1 only allowed saving when you died, although progress may have been automatically saved at key points: I was never too clear on this)
-Save location (more or less: Last building entered/exited would be fine. LoZ1's system for this doesn't really make sense)
-Viewable overworld map
-More structured quest (Allow for free roaming as per original, guide the player towards the dungeons. This would still allow for visiting the dungeons in any order, but would show the dungeon locations on the overworld map in a set order.)
-Better control of Link (Moving diagonally, spin attack)
All of that should be pretty doable. The only item on your list missing from Link to the Past (on the SNES) is the save locations. There are three locations you can start from and are given the choice of which you want at game load. I don't know if they changed this in the GBA port or not. Minish Cap probably can handle everything you want. (I don't really know, I've never played it.)
In terms of the two GBA Zelda titles (A Link to the Past & Minish Cap), A Link to the Past seems best suited to the above. Minish Cap may feature a technically superior engine, but much of its superiority would be unused in a straight LoZ1 recreation. Additionally, ALttP's graphical style is much closer to the original LoZ1, and would require virtually no graphical tweaks. Minish Cap's graphical style is quite different.
I don't know the full details as I've never hacked either game, but MathOnNapkins' recomendation of The Minish Cap was because he figured the engine would be cleaner and therefore easier to hack. I'd have to say, engine features and ease of hacking are more important than graphical similarity. (I've heard that the SNES LttP is really tricky to work with. MoN seems to think the GBA version might be as well.) In most games, altering the graphics is the easiest part. You can usually use generic tools for a lot of it.
Both GBA Zelda games seem to have a smaller overworld map than the original LoZ. I have no way of knowing if this is a hard-coded limit, or if the engine could support larger maps. The viewable overworld map is scrollable in both games, so larger maps might be possible.
As I don't know anything about thier internals, I couldn't say. Given what I've heard about LttP, it's proably hard coded in that one at least.
Neither ALttP nor Minish Cap feature the "sword beam" ability. Personally, I've never been a fan of this attack, but adding it wouldn't be possible without ASM hacking.
LttP has a sword beam type of attack, once you get the Master Sword. It's more like a whirlwind than a beam, which reflects the fact that Link's primary attack has been changed from a thrust to a swing.
Minish Cap does have the advantage of an in-game level editor (a secret item in the game obtainable with cheat devices). However, it only allows editing as Link. You have to "pick up" map tiles and place them where you want them in game. So, if I want to put a rock somewhere, I would have to find a rock, copy it, then keep holding the "copy" button combo until I was standing in front of wherever I wanted to put the new rock. I'm uncertain how this function would apply to doors and dungeon layouts, and whether an edited map is saved. I don't think using this in-game editor would be feasible for a LoZ1 remake.
While probably not useable for making the remake, the in-game editor's existance does indicate that the engine is pretty flexible, so it'd proabably be fairly easy to work with.
As for ASM hacking: I have programmed in assembly in the past. Personally, I've always preferred it over high-level programming languages, as it gives you more direct control over the system. However, my ASM experience is limited to a custom-designed 6502 microcomputer, and a modicum of DOS-era classroom examples. I kept wanting to learn more in-depth assembly programming, but my college professors always steered me towards things like Visual Studio. I'm nearly 30, and re-learning ASM for a new system isn't really within the scope of what I'm willing/able to contribute to this kind of project.
I can understand that. That said, a lot of what would need to be done could be managed without ASM. Graphics editing, level editing, text editing, (in some games, even event editing) can often all be managed with only a hexeditor and other generic tools (like for graphics editing and script extraction). It can be tedious and at some point it becomes worth your while to write custom tools, but it's not a requirement. Even in hacks that'd require ASM hacking to be "complete", a lot can be done without it.
Unfortunately, it doesn't look like anyone's made any editing tools for either of the GBA games, although Hyrule Magic looks like it could do the job on the SNES version of ALttP (although it could use some better documentation). It's a pity the same couldn't be done for the GBA version, but there you go.
Well, you can often edit games without custom editors. In fact, editors generally only exist for the most popular games or those that have be the target of a hacking project that produced one for thier own usage and later been released. A large number of hacks get made without custom tools or with a bare minimum. A good hexeditor can serve you pretty well.
Also, once you figure out a level format, writing an editor isn't that hard if you already know how to program. Especially if you're willing to keep the number of fancy features to a minimum. If you get the level format figured out, you may even be able to get some help in the tools department.