Only dual box needed for pve?

[Littleburst]

You definitely don't need 4 characters to run Flashpoints at the lowerlevels. no clue about higher levels though.

So for leveling 2 is definitely enough as far as I can tell.

[Lyonheart]

yes, two is enough until end game. Only boxer that has any experance at lvl 50 is Mercbeast ( i think hes the only one ) FPs can be tough with two companions, but doable. One thing i can tell you is that you need to make sure your companions are always geared up if you want to run FPs. Most content you can wait a level or two above the recommended level for that quest/FP to make it easier.

I'm going to run two to 50 and see how I like the end game. If i gear my characters and their companions up and find out i cant run FPs, Ill level two more accounts. But I want to know if I will even like the game at 50 before i invest like that.