Good job ! The story is great but a bit less than DarkSoul 1.

A year and a half later and I did it all, Vendrick, Ancient Dragon, Abyss, Dlc, Achievements, ...

there are 3 forms of the final boss in the abyss you have to remove a lot of his life before he split into 2 then 3 form. It's all about timing but was not the hardest boss in the game . Just redo your character as wizzard then use the biggest spell with 2 hit you should bring it to 25 % life !

And the horrible Chasm of the Abyss covenant levels. They're just too hard for me.

Didn't beat all the DLC bosses, though.

Oh, yeah, I did that.

Nope
You have to kill The old King then move special place to meet the old giant world and finally go back here and kill Cashandra if i remenber !

It's not? You mean new game plus or is there more?

it's not the end :)