I just checked google and it says 30 to all stats to unlock everything, but you can respect after if need be, though there's quite a lot of useful stuff in the ninja/magic trees so perhaps that won't be necessary even for a full melee build.
BTW, i gotta say, those remants sort of ruin the loot aspect of the game. All the gear i got is from the remnants and it's always the same because people use and wear the same stuff. Like, i wanted to try some different heavy weapon from the Odachi, an Axe or Hammer maybe, anything that scales with Strengh since that's the build i picked, but i can't because the best weapon drops is from remnants and it's always an Odachi. Same with armor doesn't seem there's any point in wearing anything other than this Warrior of the West set.
Feels a bit reductive. I don't even look at the loot from monsters i just settled with selling all common items in bulk for gold and dissassembling everything else besides the stuff i'm wearing.