With hindsight, it is surprising how these points were neglected by mainstream economics for so long. Many other aspects can be usefully added to that list. First, that stabilisation policies are crucial and that not only growth counts as significant fluctuations leave behind permanent losses.
Related to this, is the the notion that demand shocks can affect the supply side via hysteresis effects in labour supply and the capital stock via investment deceleration. The distinction between short- and long-term is necessary for theorising and teaching, but often is not useful for policy analysis models.