How long is a bit of string, a website only worth what you can get for it, having a listing will won't help much.
If an editor sees the sale of a listed site, the listing is generally removed. Just FYI... So really, selling a site listed is really just selling an unlisted site.
It's nice to add your site in a directory of DMOZ but there are thousands of sites in the first page of Google they are not added in DMOZ,,,So do not worry my friend.
Not necessarily removed but certainly re-evaluated. A repurposed domain name might not even belong in the same category and it, quite fairly, has the same status as a new listing suggestion. DMOZ listings aren't inheritable and anyone paying a premium for a domain name solely because it's already listed has a good chance of wasting it.
A site listed in DMOZ is worth no more than a site that isnt listed. There may be value in the link, however it would only be the same value as any link of equal PR. DMOZ is not the magic link that webmasters hope for.
DMoz is no longer as valuable as it was in the past. So it's not really worth much, unless the page it's listed on has really high PR - in which case you could claim it as a strong backlink to inflate the value.