Is RSI mandatory for a micro-enterprise owned by an American citizen?

I am a bit confused about RSI? I am American and my husband is English. We have a chambre d’hote under my name and as a micro-enterprise since October 2006. When we first moved here, my husband was not here full time until Jan 2009; therefor we put the micro in my name. We have filed our declarations for revenue since that time and have been given several credits, resulting in no income tax due, just the social tax. We have not received any other tax obligations. I am a bit worried about this.

I was advised that as an American, I do not qualify for any benefits and only need to pay the 8% contributions. I cannot seem to find out if this is true or not? In February of 2009, my husband registered as an auto-entrepreneur. He is a joiner and takes on just a few jobs during our off-season. We have filed the quarterly reports and paid the 23% RSI contributions. As he is British, we have now received our attestation for medical benefits (not the carte vitale), which covers both of us. I feel a bit funny about this as we are only paying based upon his earnings. However, quite honestly we could not afford it if we were charged on the bed and breakfast earnings?

I really hope you can shed some light on this, as I have searched on the net and have not found any answers satisfactory. Friends that have a bed and breakfast went directly to RSI and seem to have opened a can of worms and just received an avis pour 8,000 euros.