1. Yes, that is correct. I screen shot the email typically received from the airline with the confirmation, itinerary and receipt info after you book the ticket. That has always been accepted as the receipt on the expense report.

2. I don't THINK you'll have any issues with that. You could always submit an Insite to get guidance established for everyone since Uber use is so prevalent. I've seen guidance in the past limiting GT tips to 15% (can't seem to find it on Insite now). My guess is they'll tell you to input the two expenses, upload the receipt (if required) and explain the situation in the remarks.