I have reread your post and am now unclear of its intention. Do you have a question about whether to stay in the r/s, as per the title, or about acceptance by friends and family, as per the bold part?

If the issue is acceptance, then you need to tone down the BDSM part to avoid bruises. Your friends are not going to accept the bruises matter-of-factly unless they are all, uniformly, en masse, into stuff that is much more intense than yours. It does not sound to be the case.

Plus, if you worry about friends and family's accepting something as minor as an 8-yr age difference (8, not 28, right?), then it is crystal clear that friends and family will not accept something as major as bruises. They will continue to worry until your bruises disappear. And they will be well within their right to do so.