Questions about posting module

A while ago I created an extension to the Betrayal at House on the Hill module to include the Widow’s Walk expansion for personal use with friends, but I never got around to using it. I’m considering posting it here, but I have a few questions. First, I didn’t get any permissions from the publisher. Is it legal for me to post it here? Second, the majority of the images were scanned in and have much lower quality than the module it’s an extension to. Is that a problem? Third, I haven’t play tested it. Do I need to make sure that every single new haunt will be playable in this module?