Are the life spells and remedy and antidote hard coded ?

The game does checks based on spell number when you click on the spell in the menu. Your spell is flagged as unusable because the spell ID doesn't correspond to what is expected. You should change the spells IDs in the CMP instructions in this routine:

Code:

C3/2C1E:    C92D        CMP #$2D       (is spell Cure?)
C3/2C20:    F054        BEQ $2C76      (branch if so, check for terminal ailments)
C3/2C22:    C92E        CMP #$2E       (is spell Cure 2?)
C3/2C24:    F050        BEQ $2C76      (branch if so, check for terminal ailments)
C3/2C26:    C92F        CMP #$2F       (is spell Cure 3?)
C3/2C28:    F04C        BEQ $2C76      (branch if so, check for terminal ailments)
C3/2C2A:    C932        CMP #$32       (is spell Antdot?)
C3/2C2C:    F03F        BEQ $2C6D      (branch if so, check for poison)
C3/2C2E:    C933        CMP #$33       (is spell Remedy?)
C3/2C30:    F032        BEQ $2C64      (branch if so, check for blind, poison, and stone)
C3/2C32:    C922        CMP #$22       (is spell Float?)
C3/2C34:    F017        BEQ $2C4D      (branch if so, check for float)
C3/2C36:    C923        CMP #$23       (is spell Imp?)
C3/2C38:    F04A        BEQ $2C84      (branch if so)
C3/2C3A:    C92C        CMP #$2C       (is spell Dispel?)
C3/2C3C:    F018        BEQ $2C56      (branch if so, check for float and invis)
C3/2C3E:    8042        BRA $2C82      (otherwise flag spell as can't be used)
C3/2C40:    20132D      JSR $2D13
C3/2C43:    C930        CMP #$30       (is spell Life?)
C3/2C45:    F03D        BEQ $2C84      (branch if so)
C3/2C47:    C931        CMP #$31       (is spell Life 2?)
C3/2C49:    F039        BEQ $2C84      (branch if so)
C3/2C4B:    8035        BRA $2C82      (otherwise flag spell as can't be used)