Event Hacking question

As far as Umaro crashing the game, this was answered earlier:

You have Umaro's event pointing to 1E8F6; event pointers are relative to bank CA, so this is actually pointing to CB/E8F6, which is right in the middle of the escape from the burning house event. You'd likely see some really funky stuff before the game just up and crashed.

You said you changed his event to 1E8B4. If you look at the event dump, this location (CB/E8B4) is in the middle of an event. That event needs to point to whatever you want to happen when the player tries to talk to Umaro.

hmm this seems to be causing me some confusion. If I understand you need to have it an event thats already defined, and it needs to point whatever I want to happen when he's talked to. For ease sake at the moment, I'd like to have it so its just him saying something incoherrent and Umaro-esque (caveman gibberish).

This is the line in the event dump that i am looking at, is it wrong?
CB/1B4E: D0 Set event bit $1E80($05C) [$1E8B, bit 4]

you said it was pointing to CB/E8B4 - what am I missing?

The event field is for an offset; it has nothing to do with event bits. You said you changed his event to 1E8B4. Remember that these are all relative to bank CA, so to find the event it's pointing to, you would add 1E8B4 to CA/0000:

CA0000 + 1E8B4 = CBE8B4

You can do hexadecimal arithmetic fairly easily in Windows calculator, if you're using Vista or later.

Now, to have Umaro saying something unintelligible, you would need to write your own event for it. The captions already exist for this sort of thing, so all you'd need to do is write a caption call event. You can find many, many examples of this in the event dump.

As far as it crashing after the coin toss, I think we'd need to see what code you inserted/overwrote there. That part starts somewhere around CB/2121, after Celes stops speaking. It sounds like it could just be a typo or something, where you were trying to insert stuff at CB/2221 and accidentally did it at CB/2121.

Heres the all the hex work I have done:
In CA/AE2E (AB02E):
D0 00 C0 27 01 1C 1E 01

In CB/2221 (B2421):
Inserted - B2 30 02 27
Overwrote - 94 5A 08 5C (what was overwritten) ********

In F1/0230 (310430):
Inserted: 94 5A 08 5C (the stuff I overwrote) *********
Inserted: D0 7E D4 ED D4 FD D1 00 FE

In level editor:
On NPC 19 (umaro)
X,Y: 9,8
Event: 1E8B4
'If Mem Set'
Address: 1E80
Bit: 0

What I have overwritten is by the *******

At a glance I don't see anything wrong with that. Your game is crashing well before that, though, so you may have inadvertently changed something at a different address.

If you can't revert it back to normal (by comparing it with an unmodified ROM), your best bet may be to continue your work on a fresh ROM.