The forum will be on-topic to my site (outdoor related). I plan to have a forum that offers the latest deals and using affiliate links.
My question is will these hurt any of my page ranks if I update the forum with news (outside links) and deals with affiliate links? I'm keeping my "main site"(static HTML information site like wiki but with images) completely free of this. Could it still affect rankings?
Also, for those forum gurus out there - for security and SEO purposes, am I better off going with Simple Machines or phpbb?