Keyboard Maestro
Yes, so I saved myself about a thousand clicks converting all the presets, stuff I've download, and commercial soundbanks I have... 😉
I put them in a separate "Logic Library" folder which I access in Logic's browser, and deleted all the h2p files from those copies, and left the regular h2p's for browsing in Zebra if I want (I'm not sure whether there's any downside between the formats in use).
I always know where they go... for me, ~/Library/Audio/Presets, always.
You mean root and user - yes, this is a standard Mac feature, and it exists for good reasons - you should know why macOS does this, if you don't already.
Sure, you can put what you want in those folders. You'll only see the relevant files given the context anyway.
Sure. Everyone has different ideas of how to implement presets, whether to include their own browsers, file formats and a whole bunch of other implementation decisions - it's why plugin presets are a mess generally, and a big part of the reason for this thread to attempt to standardise preset access to some degree. 👍