The first problem is that you are moving the Macintosh game from your HFS+ hard drive image into the Windows file system. Once you do that, the resource fork has been stripped from the file, usually destroying it. When you move the damaged file into the HFS hard drive image, it's missing all the strings, icons, images, sounds, etc. that were in the file in your HFS+ hard drive image.
You are on the right track ... stuffit via the Aladdin StuffIt Standard Edition
trial, move into Windows, then move the file into Basilisk II (preferably using My Computer, not HFVExplorer) and unstuff.
I'm not certain about the solution to the problem you are having installing Stuffit Standard. Maybe someone here will know of an alternative.
PS: It's too bad the hard drive images that B2\SheepShaver\Fusion PC\SoftMac use and PearPC use aren't compatible. Or some free utility that can access a PearPC hard drive. I wonder if PearPC uses the same SCSI hard drive file format that SoftMac can use?