Based on current market, I would say its really bad. For this loan amount, the highest you should be getting is 3.85% , lowest 3.80%. If it's a subsale purchase, you can even go lower 3.80%.
UOB Combo mortgage u can forget about it. It's combination of OD facility with HL (rate above 4%). Not worth to taking even though it somewhat lower your DSR but you pay more interest in the long run.

The reducing of installment, first time I heard. My existing loan is with MBB but additional payment doesnt reduce monthly payment and redrawal can be done via m2u but charge RM 25 per redrawal.