I haven't spent too much time looking at it, but honestly, I'm not sure I agree with this assessment. While I agree with Punished Toad that a lot of the domains are just pretty bad, I think they overinflate the value of damage. Sarenrae's spells essentially just do damage. Wall of Fire is a bit different, in that it has some potential other uses, but it doesn't really stop most reasonably leveled foes from just running through it. Fire Ray does impressive damage for its cost, but a ranged touch attack, as opposed to a save, based on Wis brings it down, though not as much at higher levels, if you're investing in Dex. But still, all it does is damage.
The extra healing from the healing domain could be nice in theory, but I don't know how necessary it is. Largely I think this is the place where what happens with the final version will impact my assessment. If the game assumes cleric (from my limited playtest experience, DD at least seems to), then a little extra healing is a bit of a safety net, but if all it assumes is that you have someone who can cast heal, then I can't help but see it as unnecessary.
For word of truth, yeah, I actually agree, but I don't think it's so beyond the pale.
Compare Shelyn, as a counterpoint though. Color Spray never needs hightening for a great effect (Blindness is huge, and even if they succeed, Dazzled is still pretty good), and Enthrall and Creation are fairly niche, but ok effects. Probably wouldn't prepare them most days, but I could see situations where they're great. But also, she's got Unity, from the Family domain, for you to share your probably best Will-save in the group with someone, Protection, for divine ward, Passion, for charming touch, which is nice since clerics don't get charm anymore. I just can't see the argument that it is so heavily slanted. Now, Sarenrae isn't bad, and I think Punished Toad is sleeping on the power of Dazzling Flash, since it's a slightly worse Color Spray, though I think targetting Fort is a reasonable downside, but she's not way beyond the pale, nor do I think she's even arguably the strongest.