Yes there are risks and benefits for each and every example - as there are for the general structure of deciding on Level criteria and whether there should be easing. And the decisions made (including remaining at Level 2) are to reduce the risk to near zero. But the benefits have only been taken into account on a haphazard inconsistent basis.
Even now the Cabinet papers indicate that we have met the criteria for Level 1. Even the DGH states that the last CT was some time ago and the last case he was concerned about was weeks before that. The data to support is there. The decision needs to be made but for blind ideology and dithering.
IMO a biggie in relation to quarantine is flight attendants and pilots are not required to quarantine.