... You should also be able to select multiple sprites at once and delete multiple sprites at once, both from the object bar and project bar.
I totally agree with that. I'm someone who uses a lot of sub-folders and generally deletes or moves a lot of objects around, one by one.
This gets even more annoying when the project bar is automatically scrolling up, forcing me to scroll down and select the next object for each change.
I guess that Ashley blocks multiple picking for technical reasons but C3 should definitely bring changes to smaller quirks like these.
I don't know much about how the bar systems work within C2 but if you'd allow me to suggest something.
I think a "locking" system for the object and project bars could improve this.
By "locking" I mean blocking certain features for those tabs so that you can only delete or move objects while it is locked.
This would ensure that nothing else can be done, which could possibly lead to some sort of project corruption.