I was in the vicinity of U San Diego in California. I knew my son (back home in NY) might have interest. I simply went right to the admissions office, told them I was there and son couldn’t be, and they were happy to sign him in at admissions. I don’t see this as weird or a problem. Apart from herself, no one knows her better than you.
I don’t see any problem. I’d just put dine name of student and show up. I couldn’t match the kids to the parents on those tours and didn’t bother trying.
My D17 got sick when we were on a college trip. The morning just wasn’t happening for her so I went on the campus tour while she went back to sleep for a few hours. Literally nobody cared and it wasn’t particularly weird. When she was feeling a bit better later in the day, we took a gentle walk around the campus and I showed her where the tour had gone. It was better than nothing and the school actually became one of her top choices.