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Is it possible to point the dmoz to the index page?
If the index page presents information of equal value, (or links to it internally), to that reponsible for the site being listed in DMOZ in the first place, then it's possible. You have to hope the category has an editor that is actively editing, of course.
If you are planning a complete site rebuild then you should take care not to delete the existing pages which probably account for a lot of your traffic, maybe you should consider 301 redirects.
Optional: Once this is all done and your serps have recovered - which might take weeks -, post in the ODP forum ('Resource Zone') about the changed URL. Resource Zone is down at the moment ...