I am sorry if these have been answered already.
Is it possible for me to replace the arnory man and female shopkeeper? The replacements would have a new replacement character and a new background.
And how can I remove that beginning cutscene with the Scouring, and add text like FE6, when it displays the red screen with the sliding text? Like this: http://i.imgur.com/74J5KaH.png
And how do I change Nintendo presents at the beginning of the ROM?
The shopkeepers can be replaced using the Portrait Editor in FEditor, scroll through to find them.
If you open up FE7 in GBAGE and head to index 1153 you’ll find the Nintendo present graphic. You’ll need to play around with some of the width/height settings to get to to look the way you want it to and then edit it in a graphics editor such as Usenti in order to keep the palette.
Removing and replacing the opening cutscene is probably more trouble than it’s worth, but I’ll have to give you the standard answer: assembly hacking.
The title screen is also an image viewable in GBAGE although it’s separated into maybe 3-4 different graphics (the axe, the sword and the text are all separate).
I’m not sure how to remove the opening cutscene although I don’t imagine it’s overly difficult.
One thing that you might consider doing is just replacing the entire opening CG altogether with text graphics so that instead of scrolling through the CG is scrolls through text, maybe? Although it would still apply the ripple/weather effects so this mightn’t be such a great idea. Alternatively you could replace the text at the bottom only and maybe replace the CG with your own graphic? Anything is possible, really.