Welcome to Nasomi, Kaos!
Quests and skills on ffxiclopedia are accurate, if you use the history function. Check the upper-right corner of any page, and there's a down-arrow: mouse-over it to show some options and choose history. From there, find a version of the page from around 2006~2009, and the info there will be more accurate to Nasomi than the current version of the page. If the page was created past that point, there's a good chance it's not active on Nasomi, so i'd ask someone first. This is especially the case for some of the newer spells and NM's. (example: Tier 2 RDM en-spells don't work here, Reprisal, etc.) But, some newer stuff DOES work, like Dread Spikes / Drain II, so if it's new, it's best to ask before sinking your hard-earned gil into it.
As for a one-stop-shop of what's active on Nasomi: the best you can likely get is by looking at the Nasomi wiki. Try this page to start with:
http://nasomi.com/wiki/index.php?title=New:Nasomi