Default Open With - Google Chrome

Yeah.. That's not going to work. Google Chrome doesn't open an excel document. I suspect you mean sheets.google.com you use with Google Chrome. That will do it, but the document needs to be in your google drive.

So what you need to do is transfer the documents off the hard drive to your google docs account (or is it google drive account), then you can browse to https://sheets.google.com/ and open it from any computer.

Changing file extension mappings wont help for what you are trying to do. And Managed Preferences are dead anyways.

I don't know anything about Google docs, but in general to set default applications I recommend duti (also mentioned in the thread you linked to).

Example: Set PDFs to open in Acrobat Pro:

/your/path/to/duti -s com.adobe.acrobat.pro pdf all

If you can't right-click the file and "Open With Chrome" successfully then changing default applications isn't going to help you.

Even if you could, that would sound like a really bad idea. Formatting will break and advanced sheets will definitely lose functionality. This is something that really needs to be left up to the user to transfer files over.

The easiest to move things over to Google Drive may be to have them install the Google Drive app and move the relevant documents over to that.