So let me state what I understood and please correct me if something is wrong: Parameter meaning depend on the damage formula. 'Back row OK' is hard-coded in that formula. 'Strong vs' too.
So pretty much all 3 are hard-coded.
You are correct, but Strong VS isn't exactly hard coded, as it uses Parameter 1.
BTW how to 'translate' the addresses you use in offset in the ROM (.smc) file? For example: D1/1380-1C7F: Item names (menu), at what offset in the file is?
The offsets are in SNES HiROM format, meaning you have to subtract 0xC00000 to get the file offset. D11380-C00000=111380. You can also set up the hex editor to work with the SNES HiROM format (I use Windhex).
What 128 hit% on Excalipoor mean? Is 128 so called 'A' - always hit?
Maybe? Let me check.

Attack Type 28 (Ignore Defense)
C2/6DED: 20 F6 7E JSR $7EF6 (Hit Determination for Magic)
C2/6DF0: A5 56 LDA $56
C2/6DF2: D0 1D BNE $6E11
C2/6DF4: A5 58 LDA $58
C2/6DF6: AA TAX
C2/6DF7: 86 0E STX $0E
C2/6DF9: A5 59 LDA $59
C2/6DFB: C2 20 REP #$20
C2/6DFD: 20 B1 01 JSR $01B1
C2/6E00: 18 CLC
C2/6E01: 65 0E ADC $0E (Damage = Parameter 3 & Parameter 2)
C2/6E03: C9 0F 27 CMP #$270F
C2/6E06: 90 03 BCC $6E0B
C2/6E08: A9 0F 27 LDA #$270F
C2/6E0B: 8D 6D 7B STA $7B6D (Max Damage = 9999)
C2/6E0E: 7B TDC
C2/6E0F: E2 20 SEP #$20
C2/6E11: 60 RTS
Hit% Determination for Magic
C2/7EF6: A5 57 LDA $57
C2/7EF8: 30 20 BMI $7F1A (Check for Autohit)
C2/7EFA: A5 39 LDA $39
C2/7EFC: AA TAX
C2/7EFD: BD FD 79 LDA $79FD,X
C2/7F00: A6 49 LDX $49
C2/7F02: 3D 64 20 AND $2064,X (Check Target Can't Evade vs. Attack type)
C2/7F05: D0 13 BNE $7F1A
C2/7F07: 20 0D 7C JSR $7C0D (Hit = Hit + Attacker Level - Target Level, Evade = Magic Evade)
C2/7F0A: 20 97 7C JSR $7C97 (Aegis Shield Check)
C2/7F0D: A5 56 LDA $56
C2/7F0F: D0 09 BNE $7F1A
C2/7F11: 20 C3 7C JSR $7CC3 (Multitargetting effect on Hit%)
C2/7F14: 20 8B 7D JSR $7D8B (Target Status Effect Modifiers to Magical Hit%)
C2/7F17: 20 12 7E JSR $7E12 (Check for Status Hit)
C2/7F1A: 60 RTS I
think $57 refers to Parameter 1 which is Hit%. This is the code in question:
C2/7EF6: A5 57 LDA $57
C2/7EF8: 30 20 BMI $7F1A (Check for Autohit)
I'm guessing the "BMI" statement checks the highest bit of the Hit%. In other words, it checks if Hit% is 128 or more. instructrtrepe/Tseng calls this "Autohit". This seems to only apply to magic (Excailber/Excalipoor is technically a magical weapon), as there does not seem to be a similar check for physical attacks:
Hit% Determination for physical
C2/7EBE: A6 49 LDX $49
C2/7EC0: BD 1B 20 LDA $201B,X
C2/7EC3: 1D 71 20 ORA $2071,X
C2/7EC6: 29 70 AND #$70 (Target Status = Sleep, Paralyze or Charm)
C2/7EC8: D0 28 BNE $7EF2
C2/7ECA: A6 32 LDX $32
C2/7ECC: BD 1F 20 LDA $201F,X (Check for Autohit abilities)
C2/7ECF: 30 21 BMI $7EF2
C2/7ED1: A5 39 LDA $39
C2/7ED3: AA TAX
C2/7ED4: BD FD 79 LDA $79FD,X
C2/7ED7: A6 49 LDX $49
C2/7ED9: 3D 64 20 AND $2064,X (Check Target Can't Evade vs. Attack type)
C2/7EDC: D0 14 BNE $7EF2
C2/7EDE: 20 FC 7C JSR $7CFC (Check for Evade, Weapon Block or Elf Cape)
C2/7EE1: A5 56 LDA $56
C2/7EE3: D0 10 BNE $7EF5
C2/7EE5: 20 AC 7D JSR $7DAC (Target Status Effect Modifiers to Hit%)
C2/7EE8: 20 D1 7D JSR $7DD1 (Attacker Status Effect Modifiers to Physical Hit)
C2/7EEB: 20 23 7E JSR $7E23 (Check for Physical Hit)
C2/7EEE: A5 56 LDA $56
C2/7EF0: D0 03 BNE $7EF5
C2/7EF2: 20 E2 7D JSR $7DE2 (Check for Target Image)
C2/7EF5: 60 RTS This code probably checks for Aim, Jump, etc:
C2/7ECC: BD 1F 20 LDA $201F,X (Check for Autohit abilities)
C2/7ECF: 30 21 BMI $7EF2