Some games do have dangerous starter zones. Baldur's Gate, Dragon Age: Origins, TOEE and Demon's Souls come to mind.
I find myself a terrible judge of difficulty since I still hold that Demon's Souls and Dark Souls need a hard mode. Or anything above the default difficulty since they're both really easy. Origins on Nightmare was kind of a joke too, though the start was the roughest part due to the lack of stuff available to you.
Which is something that Amalur is at least doing right; as I get more stuff, enemies do too. Bandits now come with their own Mages that can teleport around and hitstun you with homing spells. Enemies can buff themselves with Relentless Assault (stagger immunity) before engaging. I haven't seen Rogue types do anything but I bet they might.
But, you have to admit that the way potions and reckoning mode are completly abusable in this game make any encounter trivial.
I do agree they need to be fixed a bit to make Hard (or this new Nightmare/Insane mode) harder and more fun. I disagree that the base game outside of those isn't difficult, however; there's moments where the game is a bit hard and those two serve to equalize it.
Basically, treat the two as separate entities. There's the game itself and then the mechanics the player has access to. The former is relatively fine though that may change I break into better and better equipment; the latter could use some tweaking. Potion cooldowns already exist so I'm not sure why the Healing/Mana potions aren't on that kind of cooldown as well.
And Reckoning is just too beastly. Any fight that triggers a boss HP bar should just get some strange lore reason of you being unable to twist the fabrics of fate or something. I basically just use Reckoning for bonus EXP on this first playthrough and my next ones will just forgo ever using it.