Welcome to the forum!
See
this thread for what's being proposed for the top of King Street. The most recent renderings are on page 2. Latest on this project was that the developer is still trying to secure commercial tenants.
Building heights on the Central Peninsula are regulated by Schedule G of the
Zoning By-Law, which ranged from 14-42m (depending on the location) when it was first implemented. It has since been amended to allow the aforementioned King Street project to go as high as 55m, so I get the sense that the prescribed limits don't really mean much. A future phase of the Coast Guard redevelopment looks like it could hit 19 storeys (residential) if built as planned.
Reconfiguring Simms Corner has been talked about for decades, it feels like. It's a tough location to realign due to the topography and the railroad. I'm a lifelong Johner and still avoid certain Simms Corner approaches to this day