In my opinion lvl 55 flashpoints should have their difficulty toned down so everyone, especially the new players, could enjoy them
If you tone them down then everyone still won't enjoy them, because many will get bored of them. They can be challenging the first time, in an undergeared group, but they're far from too hard. I dread to think how easy (aka boring) they'll be once everyone is full 69+.
And ibf L2P UURR DUUR, the goal is to bring new players and introduce them properly for high lvl content, flashpoints should be like the beginner's step to that direction, and not a 4 man operation raid.
There are plenty of level 50 FPs for that.
Remember Bioware, you want to attract customers, even the noobiest ones, not scare them away, this is Star Wars, not Eve online.
The same applies for the core customer base. Bore them to death and they'll leave.