Deviations from licensed font Myriad Pro specifically

I am looking at some fonts that could use some customizing. Myriad Pro SemiBOLD, but i want to reduce the sharpness of the glyphs... forgive me if glyphs is wrong.

Is there software that i can create a custom font, is there a way i can find a font already like this for purchase? Licensing of doing it myself? etc....

Thanks,

j