Yep, looks like these new changes work fantastically! Index changing, the new shields, all of it seemed to work flawlessly. If I may make a suggestion then... is it possible to also include a Copy function as well as a Switch function?
Shouldn't be too difficult. It already has the code there for "highlighting" an index, maybe for "paste" it could just be Insert instead of Enter?
That looks like a workable idea.
Yup, there are a couple things from the wishlist that have yet to be solved. The biggest thing off the top of my head would be getting the tile graphics read dynamically from the rom. I was trying to do this last year and met with mixed success. I can get it to read all the regular tilesets correctly; the only ones that are causing issues are the 4bpp ones (airship, ship). I posted my code in the other thread just to see if anyone could see what I was doing wrong. I can try to pseudocode it down to make it more readable if that would help. In any case, that can be discussed in that thread.
Yes... unfortunately graphics are not my strong suit, whether it be GB, SNES, PS or N64 graphic matters have always gone way over my head. I'm afraid I'm no help there.
I would also like to make an "arrangement" editor, for editing the monster arrangements (the screen positions of the monsters in a battle, possibly other information related to that?). The wishlist thread on that topic didn't really go anywhere.
Chillyfeez was 100% correct on his thoughts. It is the "Mystery Byte" that effects the targeting. I just tested this on the Sandhags in the Desert and changed it to 1 and the targeting was rather screwy, but its initial value of 34 is used in several different places and seems to be the code for "straight line targeting", so I guess you can assuredly change that "Mystery Byte" in Formations to Targeting Setup or something like that. In fact, I will go through quickly and mark the kind of targeting each formation uses...
Targeting List (With help from Zyrthofar's Editor)
0 - No targeting, only used by single foes.
1 - Diamond (4 Foes)
2 - Left-Right (2 Foes)
3 - Upside Down Triangle (3 Foes)
4 -
5 - Adjoining Squares (4-6 Foes)
6 - One Small Square to an Adjoining Sideways Triangle (4-6 Foes)
7 -
8 - Oblong Square (4 Foes)
9 -
10 -
11 - Square with Jutting Triangle at Left (3-5 Foes)
12 -
13 - Double Squares Down (3-6 Foes)
14 - Left Jutting Triangle (3-4 Foes)
15 - Three Sideways Squares (2-8 Foes)
16 -
17 - Full Diamond (4 Foes)
28 - Obtuse Triangle (open) (3 Foes)
34 - Straight Line (4 Foes)
79 - Slightly-off Square.
...Actually a lot of this depends on Arrangement as well. But yes... at looking at Zyrthofar's editor he has it clearly listed where which values correspond to where, but without a visual aid as he has... I imagine it would be difficult to change that on the fly.
They start in ROM at 0x73CC0 starting from Targeting Setup 00. They are all in eight bit basis, meaning that they use only half-bytes for their values.
And the Arrangement's start at...
ROM 0x71200 and it is the same case as above, except they only use 8 Bytes rather than 16 as Positioning seems to take up less space than Targeting.
There are still several game objects that have "mystery" bits or bytes that we have yet to discover the function of. It's entirely possible that some of them are redundant and actually ignored by the game (the "two-handed" flag comes to mind) but it's also possible that they do have a funciton which we just don't know what it is yet. While working on a test hack (I found this is a good way to test the actual usability/friendliness of the editor for an actual hack) I discovered completely by accident that the spells have a mystery bit (the top bit of the "effect" byte) that was causing a damage spell that had it to deal much less damage than it should. I'm planning on going through all the game objects at some point and making all the "mystery" information editable, if for no other reason than to assist with experimentation.
Yes... that was an issue that I was going to have to tackle eventually. Several of Kain's Dragon Spells had this problem, even at Power 255, I thought it was something to do with some unseen index I was going to have to scrounge for, but yes. That Mystery Flag does Exactly what you say it does. It mitigates the damage in a horrendously low fashion when activated. Phew, that actually gets rid of that worry.
While not technically part of the editor proper, getting the "complete shadow party" patch working would be such a useful tool for anyone hacking this game, particularly if they're planning on changing the plot in any significant way. That way you wouldn't have to design your plot around the limitation of who can be in the shadow party in what slots at what times.
A new Shadow Party Patch would need written from scratch unfortunately. What Phoenix did was he shoved all of the data into the normal Shadow Slot area, but he got rid of "useless bytes", unbeknownst to him these bytes were the Critical Hit Chance, Critical Hit Bonus, and "Steal Evade", he also askewed the Exp. Tables with this somehow. The key would be to finding another area in RAM that is saved to with loads of free space that could compensate the space for all 14 characters, that is the tricky part, I'd say.
And finally, on a less technical note, I've been delaying adding the overworld to the map editor, at least in part due to my understanding that it uses at least one multi-tile code (i.e. one of the bytes corresponds to several tiles in a row, f.ex. the snowy mountain tops I think it was). On a technical level this is pretty trivial to implement, but on a user-interface level I've been having problems imagining how to handle the cursor for such a situation.
That's all I can think of off the top of my head but I'll certainly let you know as I think of things 
Hmm... that does sound tricky to use, I'm sure someone can help you with that part though. Maybe just have the Mountains outline with some color to indicate that anywhere you choose on these four tiles you will be pasting a four-tile mountain top?