We did the ATV tour, which was really fun but a lot more than just riding down a dirt road with bumps. We went up into the jungle, forded the river a bunch and jumped off a waterfall. Not a technical ride but way more "exciting" than I expected.
The SUP river tour was really chill, not as many animals as I hoped but my family really enjoyed it.
We rented bikes to get around but it's easier to just jump into a Tuk Tuk to get a ride where you want to go. Plus they all use whatsapp and come grab you in 10 minutes or less.
Tierra Magnifica is worth a meal just for the view and La Luna is dining on the beach (good for breakfast).
As for the surf...
Playa Guiones is a big beach and I only had small windows/family in tow to surf near to the hotel. The swell I had looked better than it surfed. Peaks broke randomly and either closed out or backed off, I got a few good waves but nothing more than 3 turns. I was warned about crowds but there was rarely more than a couple heads sitting on the outside. I think it gets crowded when it's small, ton of surf schools in the area. Wind blows sideshore in the afternoon.
I think a little exploring will easily get you some decent surf: Playa Garza (south) has a couple reef setups, Playa Nosara is a rivermouth beachbreak that looked better than Guiones. Ostional (North) is a dumpy beachbreak with a lot of power. Don't be fooled by the locals, they say everything is 5-10 minutes away, it's more like 20-30 minutes by car.