HandBrake

Yes.

It's the Movies folder inside your user home folder.

There is a workaround on viewtopic.php?f=5&t=41161

Your source is HDR, if you want to play it on a player that doesn't support HDR, you need to enable the colorspace filter and set it to Bt.709.
I assume your 2k version is not HDR. Movie studios do a different color grading for HDR and SDR, so they won't look the same anyway.

It's a known issue in version 1.3.3. You can download the 1.4 beta or delete the queue file in /Users/yourusername/Library/Containers/fr.handbrake.HandBrake/Data/Library/Application Support/HandBrake/Queue.hbqueue

1. Yes, I'll add it soon.

2. Making good icons is hard, and requires time, contributions are welcomed but we are picky

The Mac version runs under the macOS sandbox, so it can read and write only to the file and folders the user choose in the open panel or by drag & drop.

It can't be done with the GUI on macOS.

Try a HandBrake nightly build: https://handbrake.fr/nightly.php

Nightly builds have a 10bit pipeline (if you don't enable any filter on the filters tab), so it will better preserve the original video. 1.3.3 did 10 bit -> 8 bit -> 10 bit.

HDR10 metadata passthru is supported in the nightly builds. Get the latest one from https://handbrake.fr/nightly.php

Opus can't be set to 44.1 kHz. It seems a bug in the UI, 44.1 shouldn't be a selectable value.

There isn't.

Try https://subler.org to set the file metadata.

That's another "frankenfile".

Looks like an hardware issue. Make sure the fan are working properly, try to remove the dust and check the thermic paste.

Make sure your file name has got the file extension (.mp4 or .mkv or .webm), you probably deleted it when you modified the output file name.

HandBrake can't create an mpeg program stream or transport stream file, it can create only mp4, mkv, and webm.

Set crop to 0.

I would just use DaVinci Resolve or Final Cut Pro, an editor in 2021 that trips on a vfr is a reason enough to stop using it.

Anyway, try to set the Framerate to constant in the "Video" tab.

x265 is a different encoder, most x264 options won't work. Look at https://x265.readthedocs.io/en/master/cli.html for the available options, it's the list of the cli options, but they can be adapted and be used in HandBrake.

"Alliance for Open Media" is all about AV1.
And their preferred container format is not mkv or webm. It's ISOBMFF.

It can be paused, but you can't close HandBrake. All you can do is put the computer to sleep instead of turning it off.

Update to HandBrake 1.3.3 and try again.

LookupViewService is the built-in macOS functionality that can be invoked by right clicking on some text and selecting "Look Up" from the contextual menu, or by force-touching on the trackpad. The connection is made by LookupViewService.xpc, which is a macOS built-in service, outside HandB...