I'm fairly certain this idea has been voiced across the forums, but I didn't see it championing the Suggestion Forum's top posts, so I wanted to reiterate its need just in case (especially since I didn't get to kudos it if this has been suggested yet).
There's a lot of group-forming that's not as productive as it used to be due to the division of F2P vs P2P. Furthermore, quest-flagging for things like The Tor or DQ Pre-Raid vs DQ Raid is also becoming a muddied topic and requiring a great deal of explanation to a player that joins, then after the discussion the player realizes they don't qualify for the quest due to one of these reasons and leaves with a sour taste in their mouth. While it's good that they gained knowledge about the requirement, it's not likely that informative either.
Enters the LFM Upgrade 4.0.
All quests that are P2P (ie VIP and Purchaseable) should have a special icon next to their name to inform players this is a VIP/Purchased quest. These icons could be linked to the quest packs (for instance, Delera's would be a gravestone) and also upon hover would state a pop-up with the quest pack required for those that are unsure whether they own that quest pack or not.
Also, upgrade quests that are chain-series or pre-req requirements with an additional icon representing chains (a chain symbol) and pre-reqs (a flag symbol). Get extra-savvy by making the flag reflect the viewer's status (red = not flagged, green = flagged). This would be a matter of linking pre-req quests to the Adventure Compendium. For good measure, as we do have a timer capability, throw TIMER in on Raids affected by Timer Status and make the clock green or red for Go/No Go, thus allowing players jumping into PUG Raids know whether they're on timer or not.
Lastly, I'd recommend a sellable item in the TP Store to pay for this mechanic. Although the developers don't have time to write a lot of quest guides, many f2p players aren't Foru Savvy and would probably spend some of their TP for this. Simply put, the Pre-Req quests and Pre-Raid Quests could be compiled into a book that opens up in-game. Call that book something like, "The Antioch" or "Arc of Knowledge." This book could be upgraded in later updates, but should at the bare minimum reflect quests that require the gathering of items, the flagging of other quests, etc.
Furthermore, it could be filled with recipes concerning crafting, etc. When a new crafting update is released, this Arc/Antioch would receive a modification 1-2 Updates later with more known crafting recipes. This would make it invaluable to nearly anyone and give F2P/New players a heads up on the intricate parts of quests and keys. The writing would not be terribly time-consuming and the item would help pay for the LFM Upgrade.