Default Client Path - What is it?

[billyjeen22]

The description of "To prevent postprocessing from deleting your (root) download location, select the location to protect it from removal." is very ominous sounding if I don't get it right, but it's not clear to me what it is. I'm a brand new user. I previously used sickbeard, rickrage, and sickchill. I'm a little concerned about my directory settings especially with the issues I saw with entire media libraries getting deleted :)

Here's what I have:
nzbget uses a dedicated "medusa" category, which calls nzbToMedia for PP, and stores downloaded files in: /volume1/nzb/medusa/nzbget-unprocessed-downloads/
Default Client path: /volume1/nzb/medusa/nzbget-unprocessed-downloads/
Post Processing Dir: /volume1/nzb/medusa/nzbget-unprocessed-downloads/ (identical to "default client path")
Show root Directories: /volume1/nzb/complete/TV

Do those directory structures sound ok? I want to make sure I don't end up with a bunch of deleted media. I have other media as well. like /volume1/nzb/complete/Movies/
If I'm using nzbToMedia for post processing, do I even need to specify the default client path, and post processing dir? could I link them to /dev/null (for example)?
P.S. Despite the "volume1" naming, I'm not using Synology DSM anymore, but the naming is leftover from that. This is running directly on debian 9
Thanks Folks. I'm already liking the additional features of medusa over sickchill. Feels like a huge step up.