The combat is much faster now than in earlier patches. It's improving dramatically.
As for initiative order, the only thing 5e provides is a Delay mechanic. Unless that's just homebrew. Lol. I can't honestly remember. Anyway, you can essentially drop further down in the initiative list but not move up - not during a combat.
And what would be the point? You forego a turn in order to increase your initiative for the next turn?
