Don't ever try to get rid of a runner, they are brilliant! One of mine cleared the blockage on the creek all by himself. He was getting elderly and I actually bought the next level of medicine long before the point I usually would have just to make him last a bit longer!

Adjusting clock: don't try that, you can really kill them this way! Forward kind of works if you know what you're on about (it can still have undesired results and will affect the rest of your system, too), but if you adjust your clock backward without having level 3 of farming it will take ages till new crops grow and they will all starve to death.