I flew into LIR and brought in all types of food including chicken, Meats (labeled as chicken) and dairy without any issues even though it went through the X-ray machine. I also divided up the food and put it inconspicuously in my regular suitcases as opposed to bringing a separate box of food. To be safe I had someone write a formal letter from a Rabbi in Spanish saying that we had special kosher dietary needs and to please allow it in. Not sure if this would have helped but figured it can't hurt.
I originally had a reservation at the all-inclusive westin Guanacaste with cash (not worth the points) but decided against it because it seemed like a typical beachfront hotel that I can get at any Caribbean island. I wanted to get more of a feel for Costa Rica and split my time between Arenal and Manuel Antonio.
We drove about 3 ½ hours to Arenal, a fairly easy drive. Arenal is inland with the main highlight being the Volcano, Hot Springs, Zip lining, Rappelling and other outdoor activities. We stayed at Arenal Nayara Resort ,
http://www.arenalnayara.com/ , which was absolutely gorgeous and reasonably priced. It was voted as one of the most romantic hotels in the world and on top of the list for best hotel in Latin America. The most popular hotel there is Tabacon,
http://www.tabacon.com/ . They have the best hot springs but I was not impressed with the hotel at all. The Springs Resort,
http://www.thespringscostarica.com/ , is very high end and also has hot springs but is very Disney like and expensive.
We then drove about 5 hours to Manuel Antonio which is a tropical beach town with many resorts and lots of monkeys and wildlife. We stayed at Parador Resort and Spa,
http://www.hotelparador.com/ . It was an older resort but we got a nice suite in a new building at a great price from Jetsetter. The two best places I would recommend there are Arenas Del Mar,
http://www.arenasdelmar.com/ or renting a private bungalow at Tulemar resort,
http://www.4tulemar.com/ . We went on a rafting trip and hiked the national park but mostly relaxed here.
We rented our band new 4x4 from Sixt at a much better rate than anyone else. They are privately owned but they honored my Platinum status. They only have one location in San Jose but sent someone to meet us at LIR, a 4 hour drive! There are no real highways and the roads are mostly two way single lane streets similar to our country roads with lots of curves, hills and many single lane bridges. What would take one hour in the US on our highways can take 2 to 3 hours. But with common sense and a GPS it is not very difficult to get around.