I would be careful trying to set up such metrics for yourself.
I can stare for hours at code and not getting anything done. Then away from the screen on a walk or sitting down with pen and paper I solve the problem and implement it in 15 min in code.
My point is, I would focus on a tasklist. Clear things to do at once. (Or in parallel if they are trivial.) Getting things done, not spending time doing things.
Otherwise I agree to your post.
