Pace - I think that you are right in most of what you have said BUT the level of lighting which you suggest I do not think would have helped in those conditions.
That machine is capable of 160kts. My guess is that it was probably nearer 80 - 100kts on that day. The time he would have seen any lights would have been far to late.
That building did not go up overnight. Most of the professional heli guys knows that it is there. They have probably watched the construction progress.
The pilot in this dreadful accident was a very experienced professional, no question about that. My guess from reading everything is that something must have happened before the crane was hit.
The building is here. Click on the movies icon and then down to the construction progress for your info.
The Tower, One St George Wharf
The Tower, One St George Wharf - The Tower - One, St George Wharf