On the application for Philippine citizenship

All the methods you mentioned are possible. Philippine passports are visa-free in Hong Kong, Macao and all countries in Southeast Asia.

It is recommended that retired immigrants can apply at the age of 35 and deposit 50,000 US dollars. The procedure is not very complicated, and the cost is about RMB 8000- 10000. You can take it out of the bank after half a year and buy a house for investment or something. The advantage is to retain the original nationality and hold a white card for retired immigrants; A person can bring a spouse and two children after handling it. Each person shall pay the registration fee P3 10(46 yuan RMB) every year. The disadvantage is that you can only buy buildings or townhouses, but you can't buy land, houses or lots. Also, a company must be a joint venture with Filipinos, not a sole proprietorship. But the problem of starting a company is very easy to solve.

The locals and birth certificates you mentioned are actually a way to buy Filipino birth certificates from locals, and then find someone to apply for a passport, so that you can become a Filipino completely and get insurance once you come back from China. But it also has great disadvantages. First, it costs a lot of money to find someone of similar age to agree to sell his birth certificate. Second, since you are not Filipino, you need to find someone to apply for a passport, and it will cost a lot of money not to come forward. Sometimes, if you look like a China person, you will be asked for an interview. I have a friend who asked me to sing the Philippine national anthem and take the oath. Third, the maintenance of two passports is very troublesome. Last time I went back to China, I saw a girl detained by the customs because she had an exit record but no entry record.

Both have advantages and disadvantages, depending on your starting point! Think about it.