if you wanna have fun with this thing and play for the glory of God, then its not a big deal. if you wanna get into the industry or do the pay for play thing, then yeah, as with any job, its best to have as much as you can.
its kinda like telling the guy at the park that plays ball regularly simply to have fun and stay in shape what he needs to work on to make it in the pros. its probably good to be aware of it, but a good portion of that wont represent his needs, because those are not his goals.
Pretty much everything that you just stated is equated to a working bassist.
well, my mind works, my fingers work, my bass works, and my amp works, so im pretty much a working bassist in my opinion.