As you said, the feelings of the new and old players are both important, thus I think you should make changes that take both sides into consideration.
For new players, abandonment and starvation are the main reasons why they can’t play. So in this case, you need to modify how to keep new players alive.
For the old players, destruction and lack of new things to explore are the main reasons why they lose motivation and interest. So in this case, you need to modify how to keep the old players interested and motivated.
However, the changes you’ve made recently can’t realize that for long.
The Grief discourage older players from abandoning baby to increase the survival rate of new players, which can damage older players. Better yet, reward mothers. Rewarding mothers with food if they feed their baby, so that they won’t starve while feeding their baby, and so that they can work while feeding without worrying about food. In this way, mothers can also be more willing to feed their baby rather than being pressured by the Grief mechanism.
Modification of building decay. Of course, your idea is good, but for players who like architecture, this is not good news. It is the wish of every large family to build a beautiful home, while the stone wall as part of the building, the decay mechanism destroys the family construction.
Now, the food bonus mechanism could be changed. In my opinion, the new idea is a little unreasonable. The existing food bonus mechanism can make sure that all players do not suffer from hunger, making them play this game more relaxed. As you know, eating is very important in this game, many players die of hungry due to different reasons such as disconnection to internet, an untimely call, leave the room, and even forget to eat. The food bonus can make players to avoid starving to death. In addition, the existing food bonus mechanism encourages players to cook different foods. Up to now, there are 55 foods in the game, but regrettably, many players are only eat a few foods that is easy to cook, because they don’t know the food bonus mechanism. I know how to obtain the food bonus, I am the eve in Singapore server. If you need I can make a tutorial, this is not a bug, and just people did not explore the mystery of the food. If everyone learns how to obtain the food bonus, on the one hand, new players can live better and learn how to work in this game, without starving to death. On the other hand, older players can work better and build families. That will be a suitable way to go in the long run.