Can I run the software I need to be able to make a living?
Can I run multiple HiDPI displays that I can connect/disconnect as needed without causing issues?
I honestly don't know if these are or are not available features. The first question is a muscle memory thing for me and makes me thing Windows Explorer is broken. I know the second question is not possible, so after that it's full stop. Question 3 is something I anecdotally know that has been an issue in the past, but would be problem for me if it is not possible.
Yes, I use pcmanfm on Linux and the spacebar will open the file in the default program.
> Can I run the software I need to be able to make a living?
Depends on what you do. If it's mostly design work and you require Adobe products then Linux is not a good choice. For software development then Linux is great.
> Can I run multiple HiDPI displays that I can connect/disconnect as needed without causing issues?
I never encountered problems connecting external monitors but also haven't tried connecting to an Apple monitor and makes me think drivers are probably non-existing for that.
That's not what QuickLook does. It allows the user to get a "quick look" at a file without launching a default application. Also, in macOS you get access to QuickLook from inside any application's Open dialog. That's a huge time saver when you have similar files and just need to see which one before doing a full open. Think large image files that you want to place in a layout.
Trying to attach a file to an email, but not sure it's the right one? QuickLook allows you to view the document in the Open dialog. Once you use it, it is something you will just accept as natural and only notice it not being available on other OSes.
https://www.omgubuntu.co.uk/gnome-sushi-mac-quick-for-ubuntu