I've never built a wheel and while I'd like to learn one day I'm not going to learn on this one.
On Saturday my rear wheel ate my derailleur (and bent the steel hanger in the process)*. No spokes broke at the time. After straightening the hanger I fitted the RD of my MTB (both are Shimano 9 speed) and it worked quite well. After about 130 km I heard a ping, and shortly afterwards the broken spoke snagged the chain and I came to a sudden stop. 20 km gently home and I go to change the spoke (it's a tourer, came with 3 spares). When I get the cassette off I find another has gone, and all 9 of those that come outwards on the drive side are damaged.
So clearly 9 spokes need replacing. Is it reasonable to buy 9 new spokes and lace them in and tension them one by one then true the wheel? Or is that a stupid idea? I've got time to spend on the former approach as getting the wheel to a shop is a considerable hassle.
* there are some pictures on Strava for anyone who's interested in that bit.