Creating a Facebook fan page takes about an entire 45 seconds and is a almost a necessity at this point for every business owner. Considering that 1 in 13 people on EARTH have a Facebook account there’s really no need to explain why you should be there. Pro tip: make sure you create a fan page and not a group. Groups messages don’t show up in news feeds making it hard to get in touch with members. Making a fan page will give you a lot more exposure to not only the current members but members friends as well.
That second link will still help you because it will pass extra PR to that page. But in terms of anchor text, most of the experiments I’ve seen show that the second link’s anchor text probably doesn’t help. That being said, Google is more sophisticated than when a lot of these came out so they may count both anchors. But to stay on the safe side I recommend adding keywords to navigation links if possible.
As I had a teacher at school who was always really picky on how to draw conclusions I must say that the conclusions you drew for your health situation might be true, but dangerous. For example: If slightly more women than men suffer from health deseases it could be wise to write the information toward women. But, if you take search behaviour into account thing could look a lot different: It might turn up that men search more than women or that (senior) men are more present on the net than women.