The central problem with Leith Walk is that the traffic engineers are determined not to change the Leith Walk (or any other road in Edinburgh) to make it more cycle friendly or even pedestrian.
Just look at the way in which the proposal to have a single stage pedestrian was remove from the plans, on the grounds that it would "increase" air pollution. This was done before the environmental assessment was carried out! So there was no basis for this change other than the traffic model said that it would slow down the motor traffic.
It is also notable that LRT is considered more important in the consultations than the people of Edinburgh (many of whom are also bus users). We saw this with the 20mph zones, where the local consultations and Community Councils wanted to include the major roads, but LRT objected, and LRT won. Had the whole Southside been made a 20mph zone it would far more effective, and provide a precedent for Leith Walk.