Hi Teresa,
Thank you for participating in the forum. A lot of the questions you are asking will have answers that depend on your personal situation. Also they are pretty wide ranging topics, but let me see if I can point you in the right direction.
Cost of LivingHere is a good list of necessities:
Costa Rica cost of livingCosta Rican SchoolsPublic schools and many private schools in Costa Rica have a school calendar from February to December. Some private schools are on the U.S. school calendar from September to May. Here you can find bilingual schools with web sites:
Costa Rica schools and universitiesHere is info for a bilingual school on the beach:
Guanacaste bilingual schoolsThere are many other schools that are in outlying areas, but they don't have websites.
Cars for Costa RicaYou can find almost any make or model car in Costa Rica, but in my opinion your best bet it is to stick with one of 3 makes: Hyundai, Toyota, or Nissan. These brands make up the largest percentage of cars on the road, have the most readily available parts, mechanics are used to working on them, and parts are not as expensive as other brands.
For 4 wheel drive and 7 passengers you can select:
Hyundai - Galloper or Terracan
Nissan - Patrol, (maybe pathfinder or X-Trail)
Toyota - Land Cruiser (maybe 4Runner)
These cars run from $8,000 to $ 20,000 used depending on the year and model. You would be well advised to get a diesel, as diesel fuel runs 30% less than gasoline here.
Employment OpporunitiesFrom what I understand, most professional associations here accept accreditation from U.S. states and universties. You will have to check for your particular branch of therapy for confirmation, but there is a good chance you would be able to set up a private practice.
There are many dive shops on the beach, particularly in Playas del Coco, Tamarindo, Flamingo and Jac�. Also the big resorts can have dive shops, but they may require a work permit or residency.
That should get you started and feel free to post more specific questions.