First.....Hi Head Boy...guess who
Anyways, as Cleo pointed out, I have to agree as well...I think preventing domains for a site from being blacklisted with a LL or directory, will be a hit or miss. I know for myself, as a link directory, if I come up against a 404 or other error with someones link, I will first attempt to contact them. IF that fails, I personally won't blacklist them, but I will remove them without notice afterwards. I am not sure how many others would do this though....
Technically, for link lists and directories, if a site is no longer active, I am sure they will either delete it or temporarily suspend it.