To answer your specific questions:
Is there anything I can do to facilitate getting my site listed in DMOZ?
No there is not. All submitted sites are equal, in the eyes of the editors, and get processed in whatever order the editor wishes.
If there is no editor for the cartegory can I get listed in the next higher category that has an editor?
No. There are several reasons why this isn't a good idea:
First, if the category above the one has an editor, then they can also edit that sub-category, so that doesn't help you.
Second, the site will get listed in the ONE category where it belongs, which means it won't get listed in the level above it.
Third, if you submit to the level above it, then it will probably get moved down to the original subcategory anyway, and may actually end up delaying the time-to-list.
I'm sure these aren't the answers that you were hoping to hear, but this is the way that the ODP works, for good reason.
Thanks for your enquiry.