Maybe.

The issue with spokes is that, if you are replacing the hub and rim, the spokes will probably be the wrong length. That said, I'll reuse spokes for rebuilding a personal wheel but not a customer wheel. I have to charge the customer for cleaning up the old spokes so the cost factor is diminished and I have to guarantee the customer wheel so I don't want to use "iffy" parts.

Pre-riden hubs and rims are a judgement matter. How worn is worn? Building a wheel is a fair amount of work so starting with a rim that's not round and true to begin with or one that has the a worn brake track is, to me, a poor economy. The conventional wisdom is that used hubs should be laced as they were previously. I've violated that rule with good results, but I cleaned up the spoke divots with a Dremel forst.