Is the Omni H35R good for night hunting?

Yes. Its thermal channel shows heat signatures of animals and people in darkness, which is the main reason hunters buy it. Detection range depends on the size of the target and the weather.

Does the 8K label mean the view looks 8K?

No. The 8K figure describes the pixel count of the digital sensor. What you see through the eyepiece is limited by the display and the thermal core, so expect a clear digital image rather than 8K sharpness.

How far can it really detect a target?

Nocpix claims detection up to about 1,000 meters. In practice, recognizing what an animal is happens at a shorter distance, and rain, fog or heat haze reduce range.

Does it work in daylight too?

Yes. It has a separate day channel, so you can use it as a digital binocular during the day and switch to thermal at night.

It runs on an internal battery that you recharge, so charge it before a trip. Unlike glass binoculars, it will not work once the battery is empty.

How does it compare with a thermal monocular?

It gives you two eyepieces and a more natural viewing position, but it is larger and heavier than a monocular. A monocular is easier to carry; the binocular is more comfortable for long scanning.