South of Manila, mainly be aware of dust in the air as Taal is still spitting up quite frequently, I would be sure to have a landing pad. Manila itself, just be aware of NAIA (no fly within 10km). Be sure not to fly within 20m of people. Boracay, from what I've been able to find out, is a no fly zone. Isabela should not be a problem, however the Binaue rice terraces are in the area. Since they are a UN World Heritage site, there may be restrictions near those. The same would apply to Intramuros in Manila itself. Most other areas, common sense should guide you, keep away from Malanañang, Luneta park, any embassies, military bases etc.