Yes, LG V30+ is a dual sim mobile phone.
Yes, LG V30 Plus does have the headphone jack.
Yes, LG V30 Plus can record 4K videos very easily as the rear camera has the highest video recording resolution of 3840 x 2160 pixels. You can also record 4K videos with Hi-Fi audio recording.
No. LG V30 Plus does not come with B&O headsets in India.