Is Nightfall all I need?

Topic says it all. I've tried doing a search for this but with no luck. What I understand is this:

If I only purchase Nightfall then I do not have access to the Assassin or Ritualist classes. I also do not have access to specific skills associated with the Prophecies or Factions packs. What I'm unsure of is if this also effects Elite Skills. If so, how? Are elite skills for the original 6 classes only associated with the Prophecies pack? Or does Nightfall give me access to the elite skills for all 8 classes?

Also, what other aspects of the game are not included in Nightfall? For example, does Nightfall allow access to every PvP zone? And every PvP arena system, such as GvG tournaments?

Elite Skills are broken down by game. There is 1 set of core elite skills that are available in all chapters but each chapter has elite skills specific to them.Without Prophecies or Factions you will not be able to obtain those chapter elites.

Nightfall is a stand alone game and as far as professions go you have the choice between the 6 core professions and the Dervish and Paragon. Ritualist and Assassin are specific to factions so if you want to play them you would have to buy Factions as well.

Hope this helps
:-)

Forgot to add, There is the option to buy a PvP Unlock pack from the online store for all skills to be available for all your pvp charactors. As far as pvp area's I believe you will have access to all area's except the alliance battle maps from Factions.

Also with Nightfall only, you wont have access to the prophecies and factions continents.

With Nightfall, you gain access to all Core Elite Skills and Nightfall Elite Skills. You lose access to AB (Factions) but gain access to Hero Battles. (Nightfall exclusive) All other areas of PvP are open wide but you may find it difficult to keep up with players who have all campaigns and all skills.

The only PVP zones you may not have access to are Jade Quarry and Fort Aspenwood in Cantha (Factions game).
Jade Quarry is.....dead.
And Fort Aspenwood although very fun, you don't require.

Nightfall is all you really need to have fun. You can get the other two later if you want to explore those continents and get all the skills there are in the GW world.

no alliance battles with nightfall.

Personally, nightfall is my favourite. Dervish is easily my favourite class. As for pvp, you won't have access to alliance battles which is a shame as they are my favourite type of pvp.