You are welcome, Natalie.
Let me first address: I know many of our students aren't able to access Google products at their workplace, but we might be able to do something like this with a similar product like Qualtrics.
If the Google Form that is embedded into the Canvas page is "public" (something that I would recommend and I do not believe I mentioned), "students" do not need access to Google products as a "student" for this purpose because all they are doing is submitting the form. Depending on your institution's policies, you might want/need to share Google's privacy policy in the course.
As far as SCORM content and the "Mark as Complete" feature, there is not much that anyone can do about that because (1) the SCORM content does comes from an external source and (2) "Mark as Complete" feature, while somewhat helpful, does have a limitation and it is considered to be a feature "honor agreement" or "handshake deal" and it is possible for student's to bypass.
I would recommend that you start a different question asking specifically about SCORM and "Mark as Complete" and see what others in the community say instead of "latching" it onto this situation.
Best of luck!
-Doug