Is this a surf trip?
If not, I would cut out Jaco, unless you want to party a night.
But as above says , far more to do and see nature/wildlife wise, than the pacific side and central valley.
Arenal is not active. But a lot to do in the area. Easy to reach from San Jose.
Monteverde is 4 hours from anything and is very overrated and touristy. Far more wildlife/nature on the caribe side.
Manual Antonio is for honeymooners, families, samml crowded touristy park, small beach and weekends are mainly a low key family scene or a gay nightlife.
Jaco is a not a great beach town or beach, has great surfing though, and a raunchy nightlife if you want to party.
Montezuma is out of the way, either via a ferry from Puntarenas, or water taxi from Playa Hermosa south of Jaco.
All the places you mention are connected at all via public bus, and also take a long time via a rental car, which would be the best way to see all them.
If you hit the caribe side, you don't need a car, lots more nature, cheaper lodging, less developed and far less tourist than the Pacific areas.
Raft the Rio Pacuare to or from the caribe side, its a top 10 river in the Americas and though a gorgeous valley of waterfalls and indigenous peoples.
So consider-
Arenal NP
Tortuguero NP
Cahuita NP
Manzanillo-Ganduca Marine Refuge
Raft the Rio Pacuare
Party in Cahuita, Pt Viejo and Manzanillo, and downtown San Jose.
If you surf and don't have wheels, Fly to Liberia and hit Arenal, Tenerio and Tamarindo area, or, from SJ, Arenal, Jaco, Montezuma, and Mal Pais/Santa Teresa.
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