Can I un-hide everything without selecting everything? I'm familiar with the Shift+H keystroke to hide everything except selected objects. When I reveal everything again with Alt+H, everything is selected, which is often troublesome, especially if I just want to quickly check how my object editing is reacting with other objects.

Is there any way to reveal all the hidden objects without also selecting them?
Yep.To hide and view anything on view port,you could just toggle the small eye like icon on the outliner. This is especially helpful when there are a lot of objects on the scene. see I have plane as well but I've toggled it off,so you cant see.You can toggle any number of items on or off to hide or view.Hope this was helpful