On the needle issue: I've used older needles many times and had no problems. I can't imagine a metal needle growing old in the package. I don't automatically change the needle every _____ (fill in the blank with whatever criteria you want). I change it when it breaks. I check it for snags if there is any unusual sound when stitching. And when it goes "tap tap" I think about how long it's been in the machine and check for sharpness.
It's kind of like the "use by" "sell by" dates. It's not good one day and then bad the next. It's a gradual process.
But I do probably need to change the rotary cutter blades.