Can a micro-entrepreneur add a beneficaire d’assurance maladie at any date?

Thank you for your recent assistance. I am very happy to report that following an interview at a law firm, I am going to start teaching there from September. As a consequence, I have provisionally completed the online micro-entrepreneur application form following very closely your online tutorial without which I would definitely have struggled.

1. The application procedure offers the option to add your partner and children to your health cover. I have not taken this option because my family is already covered under a carte vitale through my husband’s employment. However, it occurred to me that I should ask the question of whether I would be allowed to add my family to my health cover in the future should their current entitlement end, or is it only possible to do so during the micro-entrepreneur registration process?
2. The process offers the option for a partner to be a collaborator in the business. My husband will certainly help me in dealing with the law firm as he already does with my current students as he can communicate with them better than I as he speaks fluent French. However, I am unclear of the benefits of naming him as a colleague. I understand that he would quite rightly have to pay social contributions if I were to name him in this role, but I am not sure if these contributions are solely for a pension or also for other areas such as health cover? Online it states le conjoint est alors affilie personnellement a l’organisation autonome d’assurance vieillesse auquel le chef d’entreprise est affilie.