CR is a beautiful country. Lots of hills, ravines, switchbacks, elevation changes, etc. And the roads aren't the best or well-identified. If you're renting a car--you must have one with GPS. You'd be lost without it.
Don't knock the wife's plans. We took the family 2 years ago to Mt Arenal and did the whole cloud forest canopy zipline, hiking, ATV riding through palm oil plantations, tropical plants/orchids/butterfly gardens, touring vanilla plantations, white-water rafting (which, unlike Colorado's freezing waters, is body-temp warm, and has the occasional crocodile keeping you feeling very alive when you're trying to get back in the raft), watching active lava flows at night, visiting coffee plantations, etc.
Very friendly place. Stay away from the tourist places to eat/drink. They'll charge outrageous prices, but the rest of the country is cheap. You'll love the little "Sodas" along the roadside--little mom and pop cantinas serving the chicken, black beans and rice national dish.