You did a great job in bringing Wonder Boy to the Amiga. Even with some of the small hiccups and odd jump physics it plays very nicely, I rank the game highly and it's only some small things that keep it from true greatness.
I think a lot of people play with a two button joypad for the Amiga these days, so providing an option for the arcade style physics will make a lot of sense and people happy, but also keep the current jump physics as an option too for people who have the Atari one button joysticks, as it does make things easier.
For me, you only have to amend the jump physics, the jumping behavior of the green frogs, and squish some minor bugs for this to be one of the absolute best Amiga games and arcade conversions out there! :)