Is it possible to get notified by email or RSS of new activity in your Facebook Page?
You can get the rss feed of a page from http://www.facebook.com/feeds/page.php?format=atom10&id=xxxxx . It includes any post to your page but sadly not the comments.
They used to have that option, but not anymore. At least not for what you are asking for.
You can enter the Facebook RSS at FeedPostal.com and it will send you updates daily, weekly or monthly depending on your settings.
certainly by email. Log in to FB > Account > Account Settings > Notifications tab has a long list of different things you can be notified about via email or SMS... among which the "Wall Comments" category might cover what you want?
unless, of course, I am not understanding the question. HTH