P: Ability to view original photo side-by-side

This has more depth to it. You can use the backslash to view "Before" and Current version, but the Before comes with an asterisk. When acting on an imported image that already had some edits, LR will show you the version that was imported into the Catalog.

There is a NEED for a button that toggles all edits OFF to let you see how the unedited image looked like. It is crutial when reviewing imported edits from colleagues.

I need this feature ASAP! What am I even paying for so much...

Hopefully this feature will come across to cloudy LR soon (!). Meanwhile, I'm using a workaround which I'm sure I'm not the first to come up with but mention here in case helpful. In photo Grid view, right click on your photo and create a duplicate. You can then make your edits on one copy and use the other as your unedited reference. Now that you have 'two' photos you can view compare them side by side using  Option-C. Once you've finished editing you can delete the duplicate to save storage space. 

This is a common request for cloudy Lightroom and has been for many years. Adobe hasn't acted on this yet unfortunately. Consider searching for the feature request on this and adding your voice to it to get it more priority for Adobe to implement.