If your 8 p.m. is showing as fixed dining on the app, it's not. There is no fixed dining on the E-class ships. So go wherever you want.
If you made a reservation for those nights with Select dining, then cancel Cosmo and go somewhere else.
Someone noted in your previous thread with this question that birth certificates do not expire. My birth certificate is over <cough> 50 years old and it's still valid.
As of last July, flat fares have been eliminated.
County web site (click on rates): https://www.miamidade.gov/global/service.page?Mduid_service=ser1572618493969359
Airport website: https://www.miami-airport.com/taxicabs-shuttles.asp
Answer to your title question: no.
Appearing at opening (5:30) will result in being seated. But we had little to no wait on Apex in December. One night we got a pager and waited maybe 5 minutes.
The Silhouette used to have a coffee setup in the Hideaway, if memory serves. Not sure if any of the other S-class ships did.
Edit: a quick search shows Reflection had one, too. Perhaps after COVID, they disappeared.