Yes, Oppo F11 does have a 3.5mm headphone jack.
You can record up to 1080p resolution HD videos on Oppo F11 rear camera. Additionally, you can also record up to 720p resolution videos with the front camera of the mobile.
Yes, Oppo F11 has dual 4G sim support. You can use 2 sim cards on 4G networks at the same time without any trouble.
No. Oppo F11 does not have the IR blaster sensor support.
No. Oppo F11 does not have Dolby sound support.