If at age 55, I chose BRS and pledge my property.
To be clear, "choosing the Basic Retirement Sum" means you reduce (or otherwise cause) your CPF Retirement Account to be funded only to the BRS ($106,500 in 2025). Let's assume that's what you mean.
Then I do a full VHR of the amount I owe CPF and stop paying my housing loan using CPF. Will this amount flow to OA or it will fill up the remaining amount to FRS, and remaining flow to OA that are eligible for withdrawal any time?
Just before age 55 you can pledge your property (although you may already have a sufficiently large property charge), and you can ask CPF to reserve funds in your OA for servicing your mortgage. In other words, yes, you can cause your RA to be funded only to the BRS. Thereafter you can stop paying your mortgage using OA, and you can voluntarily refund OA dollars used for housing (and then pledge your property). All possible. You would end up with the BRS in your RA (earning 4.0% interest plus bonus interest), whatever your MA balance is, and everything else you have at CPF in your OA. (Your SA is closed at age 55.) Compulsory contributions would flow only into MA (if it's below the Basic Healthcare Sum) and OA in this scenario.
Or the best option is to do a VHR minus half of the FRS so that that amount still remain with CPF?
Best option
for what? What are you trying to accomplish? If for example you're trying to earn as much CPF interest as possible, or to secure at least decent future retirement income, what you're describing is the opposite of those goals.
I am wondering how CPF know I am selling my pledged property if I no longer use CPF to service my loans after 55?
Pledging your property means the CPF Board is informed if/when you sell it.
Also, what exactly is "pledging my property" really means? I did a AI check, it seemed like there is some kind of "legal charge" is created on the pledged property to secure the amount of RA savings withdrawn.
That's right.
Is there any lawyer fees involved to do this legal charge.
Not that I'm aware of.
I think it's the same process like a bank which I took a loan on the pledged property when I first finance the loan?
It's akin to a lender's interest in a mortgaged property.
Is this pledge can be removed, and I refund back the amount I withdraw?
Yes, you can lift the property pledge by funding your RA at least to the Full Retirement Sum.
Seemed like what I read most will be doing FRS and some ERS but seldom I know anyone doing BRS. I thought if we can generate returns greater than 4% and want to pass as much to our kids, this seemed to be a no brainer?
No, it's not a "no brainer." First, you haven't even tried to generate returns greater than 4% in the scenario you outlined because you're refunding OA dollars used for housing. OA earns only 2.5%. Second, dollars saved in CPF are uniquely well protected against creditors, court judgments, fraud, and other calamities. These asset protection characteristics have some value. Third, the 4.0% "floor rate" can sometimes increase, as it did in the recent interest rate cycle. Fourth, the 4.0% "floor rate" is not quite government guaranteed, but it's a low risk/high confidence rate. Alternatives should be assessed in risk-adjusted terms. Fifth, RA feeds into the best available Singapore dollar longevity insurance. Longevity insurance offers an extremely high safe spending level per input dollar, far higher than you can safely support from conventional, non-insurance investments even if they are higher yielding. Longevity insurance and conventional, non-insurance investments are not directly comparable.
What is your considerations when you chose FRS over BRS? A more fuss-free retirement with monthly income guaranteed, perhaps?
Spend some time learning what (high quality) longevity insurance is and the critical role it plays in (easier, more reliable) retirement financial planning.