Vacation to Belize/Guatemala

I am planning a 2-week honeymoon to Belize and Guatemala this November and was wondering if someone can give me some advice on my possible itinerary? For reference, we are two 20-somethings who love to adventure/backpack/hike.

Belize -> Flores -> Semuc Champey -> Antigua -> Lake Atitlan -> Antigua or Guatemala City night before flight home

Belize: 4-5 days?

Beach / rest / cave tubing

Caye Caulker / Ambergris Caye ?

Maybe make way towards San Ignacio -> Xunantunich Ruins / ATM cave

Flores: 2 days?

Day trip to Tikal

Semuc Champey 2 days?

Need at least full day for tour

Antigua [4 days?]

Explore city

Overnight to Acatenango Volcano [2 days]

White water rafting

Hike Pacaya?

Lake Atitlan [2 days?]

Beach, rest, relax, explore

Ziplining / canopy tour?

Guatemala City or Antigua for the final night

Night before flight home 🙁