I often drag items to the dock to open them in an application other than the default (only the finder let's you select what app to open a file in without doing

I often drag items to the dock to open them in an application other than the default (only the finder let's you select what app to open a file in without doing that). I also have an issue where if I've got multiple windows from a single app open in different virtual desktops, the only way to get to the other windows from the app is to click the dock icon - it can't be done via keyboard as far as I can tell. (And yes, it's infuriating.)