does a listing in DMOZ for a fairly new site have any weight on whether-or-not the site will be sandboxed?
Not sure it helps much at all. I had a site listed in DMOZ June or July of last year and it didn't crawl out of the sandbox until February of this year.
A link from DMOZ or any other site, even if it's PR 10 (link from a commercial site pointing to you) won't put you in or pull you out of the sandbox. The sandbox penalty applies to sites that are, in order of priority: (1) UNKNOWN FACTOR(S) (2) Commercial in nature (.com, .net, etc) (2) Competive Industry and keywords (3) New