a) they show in mine. Are you using opengl?

b) I guess. I use Firefly, sorry. No noise.

Use EzDome as hborre says. Or just use 2 environment spheres one inside the other. Same thing, just less instructions and bells and whistles. The inner sphere should be scaled appropriately and set to Visible in Camera, Not visible in Raytracing. The inner sphere is where you'll set your hdri that you want to show in scene and reflections. The outer sphere will be for the light. Turn off cast shadows in both.

c) determine where the major light source is in the hdri and place your spec and or sun appropriately. In the advanced material room you can adjust the diffuse and specular properties of the lights, so you can create a specular only light, for instance, by setting the diffuse color chip to black. You can also modulate the diffuse output of a light with a math add node. See illustration.

d) got me. I'm never in a rush lol.

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W10 Pro, HP Envy X360 Laptop, Intel Core i7-10510U, NVIDIA GeForce MX250, Intel UHD, 16 GB DDR4-2400 SDRAM, 1 TB PCIe NVMe M.2 SSD

Mudbox 2022, Adobe PS CC, Poser Pro 11.3, Blender 2.9, Wings3D 2.2.5

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