@Imelda thank you so much, I appreciate this!!
Yes. Yes. No. You may start to increase your milk supply though. I’ve been breastfeeding/pumpinh for 10 months now and I’ve never had to pump over night unless she stayed with her dad. It’s best to pump early morning and right before bed, or right after each feed. BUT since you said your baby feeds every 1.5 hrs I suggest you not pump right after.
You can start pumping, I don’t think it has any side effect. You can avoid pumping overnight but is best to pump on that time cause prolactin hormone is at is maximum so you stimulate the breast to produce more milk.