as for your first problem to see whats going on with the pinwheel boot in verbose mode in chameleon the option is -v it will run through some code and stop at an error but we also need more info. like your graphics and what version of osx your installing, if you can take a picture of the error in verbose where it stopped that would also help... you can also try -f -v combo and see it it goes further.
for the imagescan issue in disk utility select the image file, go to images tab and hit convert. save in a new location then try the imagescan from the new converted image. if still giving issues mount it and repair disk