To be frank, as much as I love the Souls games, I consider the ability to just run into areas you aren't prepared for and grab as many goodies as possible until you die a pretty big design flaw. Use up all your souls and humanity until you have a trivial amount left, then go kamikaze for loot. In that way the risk of overextending yourself and losing everything you've gained on the way, as in standard RPGs, is nearly eliminated. At any given time you're never able to lose anything but numbers that can be obtained again anywhere in the game, you always get a second chance to get them back (and with judicious use of Rings of Sacrifice, many more chances), and if those numbers are at zero, you risk absolutely nothing. So in a certain sense, Dark Souls is "easier" than other games, since your only real enemy is your patience.
To be fair, you won't know where all those items are unless you have played through the game at least once anyways. And most people are just using them to go through the game with a specialized build in a manner that they like.
There aren't many overpowered weapons anyways, most are pretty balanced with some exceptions. And those that would be are kinda tough to find for a brand new player.
I have heard of a couple people stumbling on the Zwei near Firelink and just destroying the first half of the game with it.