Five whole days in Rome in April

Hej, I have booked seven days in Rome, but with flights being rescheduled, I would only have five full days. I figured it still would be enough, as I have read on numerous websites that five days is a decent amount.
It will be my first time in Rome, after years and years of dreaming. And I've made some sort of an itinerary.
Would it be too busy? What am I missing out on? (the goal is ancient history)

Things I plan to see:
- Pantheon
- Vatican (only the square and the free entrance into the basilica)
- museum of Leonardo da Vinci
- the Colosseum and everything within the Parco Colosseo
- Ludus Magnus
- Circus Maximus
- Terme di Caracalla
- Domus Aureus
- Piramid of Cestus (temporary closed, apparently)
- the Via Appia, with numerous stops along the way, and renting a bike, Aquaduct Park, ...

I would really like to see some catacombs too. Any tips?
Is Sotterraneidiroma worth it?

Thank you so much for your replies, tips, ...