Will be driving from ohio to arizona. is it safe considering altitude changes and ascending/descending throughout drive for 30 hours minimum stopping?

No problem: Not an issue, nothing to worry about. The atmospheric pressure changes are no more (probably less) than everyone experiences in a typical airplane flight -- and those changes occur in a few minutes, compared with many hours while driving. If you have a problem with blocked sinuses or ears, there could be minor symptoms, but nothing more -- and even these can be prevented with decongestants.