No. LG V30 Plus does not have the notification light since it has the Always-On display.
No. LG V30 Plus does not have the IR Remote support.
Yes, LG V30 Plus does have the QUAD DAC which you can term as much superior to Dolby Atmos.
LG V30 Plus is IP68 certified. It means it is water and dust resistant. It is also 810G US military certified product.