Creating a new area after Kefka has been killed (FFVI Dragon's Den in FF3 US)

Okay, next problem, lads!

FF6A opens the Dragon's Den after Kefka has been curbstomped (a wonderful word that I try to work into many conversations) and I have a fairly good idea of how to go about that.

My problem, however, is not simple. Also, I may have interpreted the meaning of the addresses below incorrectly. Please either correct or point me to where I may learn, thanks you...

First, and please excuse me if my English fails to convey my intent, I wish to create a situation like the following:

1) Kefka is killed [bit xx is set, but Kefka remains a la Hidon for fighting whenever the fancy strikes you - this is just so the new area will become accessible]
2) New area becomes accessible by airship [display dialogue message $0B8D, wait for button press)
3) If ($Eventbit?($3-digit bit???)[$SpecificKefkaDead?, bit ?] is set, branch to $CA02D5 (pause for 120 units)
4) Choose 3 parties.
5) Load map $(I don't know how the maps are determined with the numbers, but I was going to use 0C7, 0DE, you know...)

My first problem is obvious: I don't really know what I'm doing, but that's why I'm asking. I'm going to mess up about 10.000 copies of FFVI before I get it right, and this is just the give me that first push.

Secondly, I've never seen a concise explanation of what something like this means:

CA/019B: C0 If ($1E80($127) [$1EA4, bit 7] is set), branch to $CA02D5

It's easy to understand $CA019B:C0 as the event address, and I know that $1E80 has something to do with the Event bytes stored in RAM from $1E80 to $1EDF in bank $7E, and I am guessing that the $127 is the event bit itself, meaning "Serves to ensure that branching always occurs 1 (always remains clear)" whatever that means..., but I don't understand the second part in []s, although the 'branch to $address is simple enough to understand.

I suppose it would help if we had bank disassemblies beyond C0, C1, C2, C3, C5, D4, E5, and EE written up and exposed...

Sorry, tangent.

Anyway, my question is essentially "How would I create an overworld airship event similar to entering the Phoenix Cave or Kefka's tower, but instead directing it to a map of my choosing, as well as ONLY having it be available AFTER Kefka has snuffed it?"

Sorry for the half-educated rambling and what-have-you above...I'm getting excited about FFVI hacking, but I'm in that dangerous partially-educated stage where I regurgitate more than I understand.