I'm not sure I'm totally understanding the question. First I would say that if possible avoid using profile documents in XPages. Just use normal documents if that's on option. Profile documents are cached by the server and I believe you'll have inconsistent requests in retrieving values after updates.
Not sure what you're looking for regards to DataSource. For xpages you should read in the values you want from the doc and then put them into ApplicationScope. You can't hold onto a NotesDocument itself in memory for long term. And this presents the next problem with profile documents. You're now caching them twice really.
If there's no need for a client app piece I suggest you switch to using a normal document. Have an xpage to update the values. On save you update application scope variables. You would then need a small code block to simple load those values if they don't already exist on your web pages. Probably not explained great but that I believe is the best practice here.
Good Luck
Dave
NotesIn9.com