It took me 3-4 Norrath's Keepers Token turnins to reach indifferent with Norrath's Keepers.
Then it took another 3-4 tokens to reach amiable.
Exactly 19 token turnins + 6 solo tasks (T1 + T2 progression) to reach kindly.
Another 10 tokens + 3 solo tasks (T3 progression) to reach warmly.
Remember that you get tokens from the progression missions and raids, too.
The raids were completely trivial at level 90 for a 90 warrior/cleric/wizard combo, except for the last one ("In the Shadows"). The group missions are easily solod at level 90.
There is a 45 minute lockout between missions. I did "Children of Gimblax" (the T1 progression mission) until "The Creator" became available (either at indifferent faction or at amiable, dont remember). With a fellowship campfire at the mission npc and teleport bind outside the instance, "The Creator" took me about 10 minutes from start to finish.
You need a party of three players to request a group mission, and a party of six players to request a raid. After requesting it, the other players can drop the group(but not the raid/mission!), they dont have to participate. You have to suspend mercenaries before requesting a raid.

