Nudism and sex life!
I am not sure there is a negative impact. If you can have an erection with no shame, and your perception of yourself improves, I think we can be more affectionate in more scenarios, which equates to being more comfortable. As far as sex life, its another step in life. For me, I am uninhibted at home, its easier to have sex or explore with no clothes on. Real people, real situations.
Being nude whenever possible, privately and socially, is bound to have a positive effect on our sex lives. As well as providing opportunities, it encourages a healthy lifestyle, which keeps us fit, and in good shape. Feeling relaxed while naked, while remaining sexually aware, adds a touch of excitement to everyday situations. It works for me, anyway!
Surprisingly little. Yes, there are opportunities presented through TN friendships that would otherwise not be there, but essentially my sex life is what my wife wants it to be, and my simply being nude around her has little bearing on what her mood may be. Now if Im nude and displaying intent, it will get her attention, but that is really no different for being a nudist than just being.
I don't know about easier to "perform" in bed, but I will say this: Although my nudist friends are not people I am sexually attracted to, becoming comfortable in those situations led eventually to becoming comfortable in sexually charged contexts also.