It generally will not take IRCC two years to respond. Likely a few months. IRCC generally only accepts certain types of H&C considerations for failing to meet RO. For example, working outside of Canada or being unable to find a job in Canada isn't accepted. Attending school outside of Canada isn't accepted either. On the other hand, if you had an immediate family member who was critically ill and had no one else to take care of them (e.g., you are an only child), that is often accepted as a reason. You can get evidence such as hospitalization records, etc. for the family member impacted.
If you want to renounce PR, you do not go to the embassy. You mail in the application:
https://ircc.canada.ca/english/information/applications/guides/5781etoc.asp
You aren't understanding how the 67 points works. This is the FSW points and you must have at least 67 points under this point system to qualify to apply for Express Entry. Whether you are selected under Express Entry will depend on your occupation and how many points you have under the Express Entry points system. It sounds like you need to do additional research. Start reading here:
https://www.canada.ca/en/immigration-refugees-citizenship/services/immigrate-canada/express-entry/who-can-apply.html