Can I renounce my US passport/citizenship and never file?
Yes and no, you can renounce your US citizenship but be aware that renunciation may have no effect whatsoever on your US tax obligations. Upon renunciation you need to fill in form 8854 that asks you clearly to state that you have filed all your taxes. If you aren’t compliant you might be able to renounce.
BUT the IRS will not let you go until you have filed up a number of years back until the date of renunciation. There are cases of people renouncing and still owing tax. Worst of both worlds. Also (in a limited number of cases) you might have to pay exit tax upon renouncing.