Shelltom my wife is filipino so if you want any advice or suggestions let me know. It would be a pleasure to help you since I don't have much expertise with anything on AFF except this topic
I wouldn't spend much time in Manila most of it isn't that nice, there isn't that much to see besides intramuros to see the spanish influence & history. We stay in Makati as there is plenty shopping to do and nice hotels to stay at. I like the Shangri La there.
What makes the Philippines truly special are the 7000 islands, you can find many locations which I would consider to be a paradise. Wonderful stretches of sand and wildlife.
Head up to the 100 islands up the northern end of Luzon it is fairly undeveloped and worthwhile even though you have to endure a long bus trip. They are building an airport nearby which will help a lot.
Another place which requires a long bus journey is El Nido on Palawan but it is quite beautiful. Puerta Princessa is the main city on Palawan and there is much to do there. Go to the underground river or do the firefly river tour which I found to be truly magical and one of the best things I have ever experienced even though it was only 45 minutes or even less. Palawan doesn't even have a cinema on the whole island. Foodwise try the chao long (most delicious vietnamese pho I have ever had although I haven't been to Vietnam itself yet).
Have a look at Bohol I have never seen so many starfishes on a beach anywhere else.
The place we do go back to every year is Boracay. Yes it's very touristy but we love it, there are so many hotels to choose from and lots of restaurants and it is the perfect location for a great cheap holiday IMO better than any tourist island in Thailand.
This is the place where you can just relax and soak it all in. Walk along the beach stop off at any beach front hotel use their sun lounges, order an inexpensive coughtail and enjoy the atmosphere.
Last year we at Boracay for the chinese new year and 90% of the hotels were fully booked, but to me it wasn't crowded there was still so much space on the beach especially around station 3 where I stay. The only crowded part is the walkway along the beach with hawkers trying to entice you to go on their tour or jetskit etc.
Lots of beach activities I go snorkelling everday when I'm there. Hotels are expensive in the Philippines but you can easily find acommodation starting from $30 all the way up $400 plus with places like the Shangri La. Lots of very good hotels for less than $100. Go and eat at the clifftop restaurant at the Shangri La it is very nice. Do go on one of the many sailing boats for an hour around sunset.
Philippines as you know is a 3rd world country so do be prepared for poverty. Most of the locals have nothing but do get to know some of them and you will soon realise they are amongst the happiest people in the world. I think it would do a lot of good for our children to see what it is like living in a country like the Philippines hopefully to teach them to be more appreciative of what they have and be more humble.
A bar the southern end of the main Boracay beach, a great place to go snorkelling.