After the initial setup it takes as much or as little time as you give it. Uploading new images and adding messages is very easy, certainly much more painless than almost any web site you manage yourself since you don't have to sweat image sizes, it handles that for you.
I've found it to be the most efficient way to post new work and have had a number of folks say they checked out my facebook posts and decided to order something. I do almost NO promotion of my facebook stuff other than sig lines here and a couple other forums, and I'm hardly a high volume poster. More promotion of your page gets more traffic, whether that means more sales is up to your work and what kind of traffic you get.
On the technical side, what you want is a business page there, which is MANAGED by a regular account. You can create a regular account and not populate any but the required information, never use that account for anything but managing the business page, and not sweat it. You'll want to configure the regular account to not be findable and auto ignore friend requests and such unless you actually want to use it. The business page you can configure however you want. Obviously if you plan to use the regular account as well, that's a different story. Think carefully about what you want as your Facebook name on the user account, it's going to show up on your business page at some point, you'll forget to post as the business instead of yourself... Set a profile picture you're happy with as the face of your business, along with a user name that works. I just use my name for the user account then Knives by Remy for the business page, keeps it simple.
Most of what people think is Facebook datamining and somehow figuring out who they are and who they know is actually caused by their real life friends and associates having FB scan their email contacts lists. If you're in someone's email contacts and they have FB do that, FB now has your email address and WILL send you email if you don't have an account yet, or an email suggesting you add these people you may know... Folks freak out because FB somehow knows who they are and who they know and OMG WTF BBQ. That's not to say FB doesn't keep track of everything you do on there and who's profiles you visit, who you're friends with, what you "like" and then use that data to maximize their advertising profits. They just aren't doing anything particularly sneaky.
