I’ve made a post about improvements that could be made to HKG operations. HKG Ops
To comment on your point 1, you’re thinking about current operation. We need to think ahead into the future where T2 is completed. At that point I’m sure all three runways would be used simultaneously. Just like in the real world you could have ILS simultaneous parallel independent/depended approach
Point 3 we would just have to wait for the dev team.