mine is semi flexi home loan, for the advance payment, does it reduce the interest?

Yes just make the payment to ur home loan account and any excess payment will be counted as advanced payment.

Yes I am using classic m2u website.

but i notice that no matter how much advance payment i had made, the interest paid monthly is still about the same. why is it so?

if my current home loan installment is around rm3k for another 32 more years to clear the loan and I can afford to pay rm6k per month for my home loan.

which ONE of the options below will help me to save the most interest?

1) refinance to a shorter tenure - says 32 - x years for a monthly installment of rm6k
2) just simply pay extra than the initial monthly installment for the amount of rm6k to reduce the interest?

if refinance with another bank vs refinance within the same bank (such as to lower the loan tenure), does refinance with the same bank will have less legal fee to pay?