Yes.

Yes , currently market lowest is 3.75% for non zero moving (mean you need pay legal + valuation) or 4.2% for zero moving (bank absorp everything)

This is the best rate from some banks like CIMB, Affin and AmBank. These 3 banks are offering the least competitive housing loan rates at the moment.

But if you shop around, you should be able to get 3.85% from Maybank and Public Bank, maybe even UOB, Alliance Bank and Hong Leong Bank. RHB offers 3.90%.

Please take the time to shop around, 0.30% is a huge difference over 34 years, especially since you are going to be borrowing nearly a million Ringgit.

Sign extension letter.
3.85% for subsales, correct.

It on daily rest, mean will take effect on 15th December for interest saving
You can sign the letter offer as long as banker let you sign cause normally bank will only auto cancel your application after 1 month.

Alternative you may ask banker to give you extension letter.
3.75% promotion end by 31 December , not sure will be any extension, but you should be able to grab 3.85% at least for your loan size
3.75% promotion end by 31 December , not sure will be any extension, but you should be able to grab 3.85% at least for your loan size

Yes, MRTA compulsory for 3.75%, for PBB is 3.85% and MRTA is compulsory too