Is it possible to purchase another Projection (eg. ProFootballFocus) for the DA acquired through 4for4 and, if so, how would I go about doing it?
Yes. After you sign in through 4for4.com, click the link to the Buy page (https://draftanalyzer.com/Buy). Deselect the Draft Analyzer as you already have that with your subscription. Add ProFootballFocus ($6) and any site add-on if you want to use the league/draft sync features (not required as adding leagues is pretty easy as is manually entering draft picks for off-line drafts). The more add-ons you buy, the lower the price per add-on as you will see in the Buy page. Let us know if we can help with anything else.