On point 9. I’m saying the manager likely will duck you if you just say “I’m here to apply” so if you want to get face to face with them you should just find any employee and tell them “I was in the other night and I wanted to talk to the manager about it”.
That will get them in front of you, then give your pitch.
If they deflect and say “well I’m not the hiring manager” ask when they’re in.
If they’re still playing games you have two options
1. You can just bounce because if they’re going this out or their way to avoid hiring then they’re probably toxic and the architects of their own misfortune anyway.
2. Say you understand they’re busy and that you’d like to leave your resume with them and they can reach out if they need you.

As a disclaimer some restaurants are seasonal so they may be entering either a contracting or expansive phase with hiring.
When you interview you should ask the manager if the restaurant is seasonal and if so can they describe the seasonality to you.
If you’re working on mostly tips you don’t want to be filling the shoes of people who left when all the meat came off the bone and walk into the slow season.