How fast am I moving through space/time, potentially?

I know this is a gross oversimplification and does not happen, but imagine that for a moment, all the directions of spin, orbits, vectors, directions of expansion et al ALL lined up, travelling in one direction so the various velocities added up neatly. The rotational velocity of the Earth, plus its orbital velocity around the Sun, plus the rotational velocity of the Milky Way (or our part of the spiral arm around galactic centre) plus the speed of the galaxy through space plus the rate of expansion of space/time itself. Just how fast would a person stood on an imaginary point along the equator - for a moment - actually be moving. Or if that doesn't work, how fast would a point at rest to the motions of the Universe appear to me moving to an observer moving along the combined vector? Is there even an answer? I need an astrophysicist.