I set my page up a couple of years ago and adding the discussion board was easy then...because I don't remember it being a problem. BUT, I tried the edit page function on my page and didn't see where it might have come from. Sorry...have you tried the FB help function?
You can define your settings to allow friends to post to your wall as someone said here...but it is true that people can find you by stumbling onto your page, perhaps because they are friends with someone else who is friends with you. I'm not sure you can escape that.
With Link Love, when you get an email that indicates someone has posted in a link love discussion you have already posted your links on, others can find you as well. If someone in this group would like to weigh in on this as well, that would be cool. You might consider experimenting with an actual friend to test some of the settings... FB is always a learning experience, for sure. Oh, and I don't think it's rude to remove a post. I'm sure your friends will be commenting on your posts (beautiful photography btw!) in a positive fashion...and this creates a nice...'come back and see more' relationship.
The problem I have always had is that because your personal page and your business page seem inexorably linked, it bothers me that activities I do as "my business" like attending one of my FB group functions, appear as recent activity on my personal page...which I tend to keep for my family, and friends outside of my busines life. I don't want to spam my friends with every step I take as 'my business'. I know you can choose to post as you as a person, or you as a business, as a way to get around that...a little cumbersome to remember to change back and forth, but it is probably a fix for that.
Sorry I can't give more exacting answers. Although FB allowed me to meet wonderfully artistic people, and provided nice feedback comments about my creations, and was a great upper on helping with inspiration, it unfortunately didn't increase my Etsy sales. So for me personally, I spend much less time on it now than I once did. It works wonders for some shops, so it certainly can be a useful tool.