booking online or directly

I will be travelling to the Philippines at the end of january/start of February for 3 weeks. I plan to visit Borocay and El Nido during my trip but have a few questions. Will i be able to find accomodation when i get to the island or should i book online before hand? i have heard that it can get booked up especially on Borocay.

I have booked my flights but i would rather book everything else when i get to Manila is this possible?

I am thinking of going to El Nido first and then Borocay can anyone recommend the best mode of transport? is it possible to fly from manila to El Nido - El Nido to Borocay - Borocay to Manila?

I visited Thailand recently and i know you can book most of your accommodation/internal flights/boats through agents in Bankok. Is this the case in Manila?