I'm a little confused by what you actually want.
Can you make money from facebook? yeah. look at all the #bossbabes raking in the millions. Seriously though, if you run a group with good engagement, then you can probably make some money. Chatting to others there are a few coupon groups that the admin make quite a bit. However, I think facebook has many algorythms, one of which is that I think it de-promotes links outside of facebook. So if you are hoping to make millions by linking to amazon then you've probably missed that ship.
If i had a group with good engagement I would explain what I was doing (trying to make a bit of cash) and that there would be the occasional link that you might get paid if people click through and buy.
You are more likely to make 'proper' money taking the metrics from a large group and using them in your media kit to entice pr companies/marketting companies to pay you to do a promotion to your group. However, people are fickle and you might find they don't like being sold to and leave, reducing your attractiveness to PR companies.
I'm not sure you can take a group/page and 'turn it into a forum'. You could start a forum and link it to the FB page. People tend to enjoy the ease of Facebook but they don't like how it is linked to 'them' where-as a forum, you could be anyone.
Thanks,
Former Prime Minster John Major.
