Hi there, traveling to Costa Rica via Liberia for 6 nights with 2 older teens. We are planning on a beach and adventure vacation, renting a vehicle and considering exploring Arenal Volcano, La Fortuna Waterfall, Monteverde Cloud Forest + experience hanging bridges, zip lining and maybe hot springs:
- Night near one of the beaches (Hermosa..) then head to La Fortuna area the following day after a few hours at a beach for a couple of nights to visit Arenal Volcano and La Fortuna Waterfall. - Move on to Monteverde Cloud Forest (zip line and Hanging Bridges?) - spend the night there and then head back to the beach area and then depart Liberia.

Any thoughts on this plan? ideas, renting cars and insurance, etc?

That's a lot to pack into six days. I fear you'll spend a lot of hours in the car. Do those six days include your travel days? I would choose either Arenal/La Fortuna or Monteverde.

A bit overly ambitious . I have 7 days, including travel.

Personally with such a short trip, I'd skip Monteverde. There's tons to do in the Arenal/La Fortuna area including ziplining at Sky Trek, natural hot springs like Tabacon or Eco Termales, and the Mistico Hanging Bridges. Desafio is good for other tours if you're interested.