This isn't exhaustive, partly because this is hardly a FAQ and partly because I can't perfectly remember all the text that is used in the game and haven't time to check thoroughly.
Some of the dummied lines are the sort of placeholder text and odd snippets you'd expect. So we have fragments like these:
Received " " Materia!
Received " "!
DEBUG MODE
NOJIMA
Temporary stopper
October 7”
doing it
Thudthudthud!!
That ???? is supposed to come in.
"Morph Menu"
"This is the end of the Test Play.
There's some extra text apparently associated with the debug rooms too: presumably at one time Kato's room was even weirder...
We're working hard making
the deep {BLUE}.
Wait a little longer.
nyuk‚nyuk‚nyuk…
Welcome to Kato's room.
That doesn't really matter
all that much‚babushika.
{NEW PAGE}
Get ready‚caped crusader‚Nya-ha‚ha……
Don't think you'll get away so easy.
Now on to a fascinating new world…
Let's go!!
You won't regret it.
Another couple of debug room fragments are 'Aho' ('retard') and 'Baka' ('idiot'): charming. Oh, and there's a reason Cloud can end up being called 'ster': it's what looks like a failed/aborted attempt to modify name variables, so 'Cloud' was supposed to become 'Cloudster', or if you call him 'Tim', 'Timster', etc. (The Japanese Chrono Trigger does something similar to form the name of Marle's ancestor; in English we just get the fixed 'Nadia'.)
{CLOUD}ster
{BARRET}alator
{TIFA}lonia
Princess {AERIS}
Little {YUFFIE}
Cait Sithers
Ol' {CID}
{VINCENT}
There's text left over from the demo disc, in which Cloud had to help Biggs as well as Jessie during the first mission:
Biggs
“I just let my guard down for a minute…
And someone got behind me…”
I hoped to find some dummied text in the freight carriage that might help explain the Cargo outtake; there is a bit... After "It's not ready yet... Whoa!" there's a blank, then 'Shut-off the switch in this position.' (No idea...) Finally, there's what looks like debug/placeholder text:
We can escape from the train event…
Did it!!
4th failure
3rd failure
2nd failure
1st failure
Escaped
What turns out to be of greater interest is some extra dialogue with Jessie. In the final version, after thanking Cloud for helping her at the reactor she leaves; this is how things might have gone:
Jessie
“Say‚thanks for helping me
back there at the reactor!”
{CLOUD}
“Yeah…”
{CHOICE}That's OK
{CHOICE}Quit thanking me
{CLOUD}
“Don't mention it.
{CLOUD}
“It bugs me when you thank me.
It's just a part of my job.”
Jessie
“But‚I…
I was just glad…”
Jessie
“{CLOUD}……”
{NEW PAGE}
“You're right.
We're just partners.”
I get the impression Square was intending a more developed relationship with Jessie: there's a lot of blanked-out text associated with the railway map, and I don't recall all this from the finished game:
{BARRET}
“Yo! What're ya doin' now?”
Biggs
“uh‚{BARRET}…
We‚uh…”
Wedge
“We can't do it.
We just can't do it.”
Jessie
“Don't worry!
Don't get all worried!”
Jessie
“{CLOUD}!
Let's make the mission work!”
Jessie
“{CLOUD}?
When this mission's over…”
{NEW PAGE}
“Why don't all of us take a long vacation.
Maybe we could go to a hot springs somewhere?
Yeah…
I don't know…
{CLOUD}
Yeah…
If I feel like it.
Jessie
Alrighty then!
It's a date!
{CLOUD}
You never know what lies ahead.
Jessie
…how lovely.
I might just have to tempt you‚then.
{BARRET}
Yo‚you all done flappin' your gums!?
Go!
Get on that train!
{TIFA}
{CLOUD}…
Don't be so distant.
Everyone wants to be your friend.
I'm sure…
{BARRET}
Damn‚man!!
I'm here to fight!
Don't care 'bout bein' nobody's friend.
{BARRET}
Let's go!
Don't be late!
There are some places where dialogue has been sliced apart and familiar lines lead into unfamiliar ones:
{CLOUD}
“So let {BARRET} and his buddies
do something about it.”
{NEW PAGE}
“It's got nothin' to do with me.”
{BARRET}
“You damn right we'll do something about it.
N' you stay outta this {TIFA}!”
Again, on the train during the second mission; this leads into Barret's “Yo‚ Mr. Know-it-all‚ big time SOLDIER! You oughta know the area 'round the No. 5 Reactor‚ right! So let's hear YOUR explanation!”
{CLOUD}
“What do we do until then?”
{BARRET}
“The hell do I care whatcha do?
Just siddown an' shu'up.”
{CLOUD}
“Sorry‚but I have a thing against
sitting down in trains.”
{BARRET}
“@#$%! Do whatever you want!”
{CLOUD}
“What do we do after we jump?”
Now this is striking. In this version President Shinra's broadcast gets a bit more attention...
President Shinra
“The terrorist group called AVALANCHE
has claimed responsibility for today's bombing
of the No. 1 Mako Reactor.”
“It is also predicted
that they will continue with similar terrorist
activities in the future.”
“But I want the citizens of Midgar to be assured.”
{NEW PAGE}
“Shinra‚Inc. has mobilized SOLDIER to protect
you from any violence and thereby…”
{TIFA}
“Will you please come back?
Ah‚wait. Please wait.”
{NEW PAGE}
“The president of Shinra
is going to read a statement.”
{TIFA}
“The next time we'll be up against…SOLDIER.”
{TIFA}
“{CLOUD}‚then you'll help us?”
{CHOICE}A promise is a promise
{CHOICE}But I still hate {BARRET}
{TIFA}
“I hate {BARRET}.”
{TIFA}
“You came to tell me that?”
{TIFA}
“He's not a bad person.”
{TIFA}
“Don't worry.
I'll talk to him.”
It looks as though things were going to get pretty fraught:
{TIFA}
“{CLOUD}…
I can't believe this is goodbye.”
{BARRET}
“There's your money.
Now get the hell out!!”
Maybe this is where 'From pinball' would have gone:
Biggs
“You know‚{CLOUD}.
{BARRET} says those things‚but…”
{NEW PAGE}
“We're really unstable right now.
If SOLDIER were to show up‚they'd whoop us.”
Wedge
“{CLOUD}‚ya gotta help us.
I'm really scared.”
Jessie
“{CLOUD}….
It's painful.”
{NEW PAGE}
“Why is that?”
{CLOUD}
“What's goin' on?
It's really shakin' a lot…”
{CLOUD}
“{TIFA}?
{TIFA}?
Where?
{CLOUD}
…I'm going out…
Here's something else I don't recognise:
Please change the disc.
Save your game?
Yes
No
Please insert disc two.
You still haven't saved your game.
Continue playing?
…over…
It's all over…
…everything…
Everyone…everything…
all finished…
Now everything
will begin anew…with me!!
Besides this (and some other material I haven't included), there are an awful lot of blanked-out text lines, which of course raises the tantalising prospect that they might still have dialogue in the Japanese version of the game—and I've just checked, and some do, but the text viewer I'm using (FF7TV-3) can't display the Japanese text; all I can see are PCs' names... Square really went in for buried treasure back then.