The quoting also breaks if you have double quotes in your filenames, which was also my case, that's why all special chars were escaped in my list.txt file.
By the way, it might be useful to someone to know how to do that, cause it took me quite a long time to find out:
find here -type f | sed "s:[\ \',\"]:\\\&:g" > list.txt
If your filenames include other special chars, you can add them in the left part of the sed expression.
Actually I wasn't thinking of all the unhealthy characters in the filenames, your post mentioned space, the most common unwanted character, so I advised accordingly. Think of filenames with newlines embedded in them, dealing with them will be a different chapter.
I'd strongly recommend to rename those bad filenames asap, to avoid future troubles.