Speaking of the root/5th power chord; do you realize that it can also function as a root-less (another instrument can supply the missing root) 7th Sus4? This is especially true if you play it in an upper register like on the D and G strings. You can resolve it by simply playing the resulting tritone (like a power chord, but with a flat 5) that occurs with the implied flat 7th/maj. 3rd.
