We never use debit cards. We use credit cards with protection and get cash back when grocery shopping. We really use very little cash nowadays. Everything is paid with credit card and we have always paid it off in full every month so no interest fees. It's just easier to manage rather than cash.
As for as medical insurance, one thing you don't want to do is to domicile in South Dakota if you're not on Medicare yet. There is no country-wide insurance to be had in South Dakota. Go to IRV2.com and look at the full-timing forum for long posts about this problem. Texas or Florida are the states to choose for good medical coverage country-wide.
Good luck!