I count 25 available tokens per day. A few notes on the heroics:
Poisonous Strategy can be fairly difficult with two players if neither has CC. You must defeat two elite Jedi at once, they hit hard, and they love to use AOE which will kill your companions quickly.
Old Enemies can be easily 2-manned with a healer, and would likely be soloable by a healer and a well-geared companion (mine isn't quite there yet). The trash on the way to the boss is harder than the boss himself; stealth helps a lot.
Lights Out is very easy to solo if you don't mind dying a couple of times, or if you have an instant in-combat stealth escape button. The objectives are guarded but can be clicked while in combat.
Freeing the Fallen is the easiest of all of them. The Jedi Master's damage is very low, and most classes can probably solo this with the appropriate companion.
The artifact-level components granted by the heroic quests are BoE, and if you don't need them they do sell pretty well on the GTN. The credit rewards for the quests themselves are 7k-14k; the total for doing all dailies is around 150k/day.
