So, the Weasyl staff made a clarification on their Collections feature:

http://forums.weasyl.com/vbulletin/showthread.php?2043-Weasyl-Hotfixes!

Term said:

We've changed our wording in the collections feature guide. We want to clarify that this is NOT a mandatory feature. We've removed the old requirements to post art made for you. We encourage the use of the collections feature, however you’re free to upload art to your personal account, so long as it has been made for you, or by you. In the event you are uploading art done for you, we do suggest that you place this art within a folder labeled as such, though again this is not a mandatory rule. To read more about collections, go here:

Which is actually something I've been thinking about the past few days. I've hesitated to post anything, since admittedly most of the stuff on my FA gallery is commissions from other people (in fact, nearly all of it is, because I am a terrible and lazy artist), and I didn't want to post other people's art when I could put it in my Collections. The only problem I really had was for the pieces whose artists don't have Weasyl accounts, but since they've clarified what you can and cannot post in your own gallery, I think I'll be uploading stuff very soon.