Costa Rica Day Tours

All,

Need some help!! I am going to Costa Rica in early April - first time there. I had a few questions about planning travel and activities during my trip. To provide some more context, here is my itinerary:

(Day 1) Arrive in San Jose at 12pm. Spend 1/2 day in San Jose.
(Day 2) Leave San Jose early morning and go to La Fortuna/Arenal
(Day 3) All day @ Arenal/La Fortuna
(Day 4) Leave La Fortuna/Arenal early AM and go to Monteverde
(Day 5) All day @ Monteverde
(Day 6) Return to San Jose
(Day 7) Fly back home

Few questions:

(1) What would you suggest for activities/excursions to do in each of these areas? (e.g. canopy tours, hikes, etc.)

(2) What is the most cost effective way to book excursions/tours? Should I do it online before I leave for Costa Rica or to do it there through hotel concierge? Any one have any suggestions on reliable places to book with decent prices?

(3) Most of the excursions I have seen online seem to start early morning - which means I cannot book them on travel days - Day 1 (San Jose), Day 2 (Arenal) or Day 4 (Monteverde) - as I reach there early afternoon. What can I do for the half-day in each of these locations?

(4) What is the best mode of travel between these locations? At this point, I think taking the shuttle would be easiest as it goes directly between the hotels. Is Grayline preferred or Interbus?

(5) I see from previous posts that San Jose is not a very touristy place. Any suggestions tours/excursions to do nearby but outside of San Jose during my two half-days there?

Any inputs are greatly appreciated!!

Thanks in advance!