interesting report. You mentioned that you was not able to get to Punta Sal because of a guard gate to the new resort. If you turn left a few meters before the gate, there is a dirt road that takes you directly to Laguna de los Micos (monkey lagoon) and there you have excellent birding and wildlife in general (monkeys, oters, etc). Once you get to laguna de los micos, you can hire a motorboat to take you to punta sal (which is still far) or go for a ride in the Lagoon , which is cheap to do and you can see a large variety of aquatic birds, crocs, monkeys (white faced and howlers), etc.
Near every national park or jungle, there is usually a guide for hire, these people are well worth the money, they are cheap (you need to negotiate before, although many just want a tip depending your findings that day). It is very important to have a guide, for example , to find the Colibri esmeralda, they can take you right to the places to find them, they can direct you to nests (if that time of year), etc etc.