Did you actually suggest it to DMOZ? If you didn't, then it's very possible an editor hasn't found it yet. But you're welcome to pick an appropriate category (I recommend that you pick the most specific one that seems to fit most of the site content).
And if you did, what category? Without that information, we can't check on its status. With that information, we can at least tell you whether an editor has reviewed it yet (for whatever that is worth.)
As for the search engines, ... I think you're depending on ten-year-old techniques, that the spammers have long since abused to death and beyond. But we don't worry about search engines here: the ODP is a different (perhaps complementary) way of organizing the web, and we focus on doing it well. You should probably look for advice from someone who spends more time manipulating search engine results.
One more general observation: you don't add a site here. You just suggest it. Editors are free to consider public suggestions, but remain solely responsible for placing and describing sites. The frustrating thing for many people intent on their own sites is that editors are, um, intent on the ODP instead: so considering public suggestions for listings may take a long time -- years, even, from the time a site is created. (Your suggestion may shorten that time, but probably won't shorten it as much as you'd like.)
