If you want to start a Hard Mode run from scratch, set any of these addresses to 0x01.
File 1 - 0x0210AA2A
File 2 - 0x0210AA2B
File 3 - 0x0210AA2C
It sets a CLEAR flag on the save file, even if you haven't started a game. This is all that's necessary to start a Hard Mode game from scratch, the following is just to fix a couple problems that crop up from carrying over non-existent data.
You'll probably want to modify these addresses to these values,
0x020F7228 0x0008
0x020F722A 0x0100
0x020F722C 0x0200
0x020F722E 0x0004
0x020F7230 0x0001
0x020F7232 0x0002
This sets the control scheme to default. If you start a New Game from the clear option, it will try to write the values from the existing save, resulting in blanks for all of them.
Also, it's necessary after starting to set 0x020F7255 to 0x00 in order to get the auto-equip and the extra dialogs, but I think you already knew that. Here is a code for AR that will set it to 0 when you start from the CLEAR icon.
920F7254 F0FF0F00
220F7255 00000000
D2000000 00000000
One other thing of interest is the save file's time values:
File 1 - 0x0210AA58
File 2 - 0x0210AA5C
File 3 - 0x0210AA60
The format for the save time is value /60 = time in seconds.