Are you trying to actually learn Linux or just how to use Linux to get other work done. Learning how to use Linux to get work done doesn't require a 'need to fiddle' as you put it, but you're not going to really learn actual Linux (as in how the kernel and core operating system works and hangs together) without getting your hands dirty and breaking a lot of things along the way.
Yes, but do you actually need to know that? I know that, I've been using Linux since the whole thing fitted on four 1.44MB floppies. I don't *care* though, and if my machine is fatally screwed up I just bust out the latest Ubuntu LTS, flatten, and reinstall.
I haven't got time to muck about with rescuing a broken system. I've got stuff to do.
Do you actually need to know JavaScript? Or C? Or Japanese?
As I said, if Linux is just the OS you use to do something else, then no. If your job/hobby is to actually develop Linux or tools that tie very tightly to Linux and how Linux operates, then yes.
