In Nuendo you have ‘Add Group Channel to Selected Channels’, 'Add Fx channel to selected channels and ‘Add VCA channel to selected channels’ in the mixer which adds group/fx bus automatically.
100% agree. IMO Steinberg could perhaps consider doing an overhaul of the project browser window in order to create a more structured overview with elaborate search functions and visibility presets. In it’s current form I’d hazard a guess that the project browser doesn’t get used a lot, but if it was re-structured it would probably get used all the time. If they could add more vertical columns so you can see all nested data simultaneously and also include search and visibility tools on the toolbar they could come probably come close to some of your requirements.