New selection/delete option

I've downloaded some amazing custom rides, but a big problem I have is when the maker adds speakers with music/sound effects, I like to add my custom music but when I do, it clashes with the music coming from the hidden speakers, when rides are built in a building I find it almost impossible to track down all the speakers, the terrible camera angling doesn't help either. when I eventually find one to delete, no matter how many times I click on the speaker, the whole ride or scenery highlight, or nothing highlights at all.

A simple solution would be if I could select all using the little square at the bottom, and when the pop up listing how many items comes up, if I could click on that and then get a list of every contained item, I could them click on the speakers from that list and hit delete.

This would also help if you make a huge ride scenery then change your mind - for example you make a ride with a forest then change your mind on which trees you want, currently you would have to find and delete every single tree, with the suggested option you could find the trees in the dropdown menu in the list of selected items and hit delete all.