totally lost track of this thread in the shuffle. What ysalex said.
and also how the tri's will come back to haunt you - in certain areas they will cause 'pinching' when you've subdivided a few times. So any area that has triangles or junctions where five edges meet in one vert, you'll want to try and hide in an area that isn't super visible or doesn't need a lot of detailed sculpting.
Like right now on the back of your hand off of the base of the ring finger, you have a vert where six edges meet. It's easier to avoid layouts like this... but check it out, step up a few subdivision levels and then start sculpting over that area. Notice how that section doesn't smooth/flatten easily and doesn't sculpt out as easily as the rest.