Unfortunately, the debugger gives me nothing about the WebGL issue. I even started digging into the browser console, but couldn't make sense of it. I have spent many, many hours trying to figure it out (hours I needed to spend play-testing) and unfortunately, it's on of those errors that you Google and it says "not many search results found." Those are always scary!
Anyways, I'm going to fix it even if it means rebuilding the game in a new project. But, with the info you've given me, that might not be necessary.
Also, thanks for clarifying what you meant about the orbital aim. I just did a full playthrough and it worked fine for me, so I'm glad you mentioned the orbital speed part, as that's probably the key. I didn't have much speed in my run. Pretty sure speed is OP, except, as you've found it (unintentionally) has a negative impact on your aim. Thank you! : ]