1. Bowls are not returned after consuming rabbit stew.
2. The Comfort effect cannot eliminate or grant immunity to the corresponding negative buffs.
3. Sugar cane cannot be planted on Rich Soil without water.
4. Cacti cannot be planted on Rich Soil.

Please open one issue per bug next time, as it's easier to resolve them that way.

1. Bowls are not returned after consuming rabbit stew.

Oops, that was an oversight. Fixed on commit 4f725b1, should be out on the 1.2.9 patch. 👍

2. The Comfort effect cannot eliminate or grant immunity to the corresponding negative buffs.

Comfort no longer does what you described. Nowadays, the effect grants you natural regeneration regardless of your hunger level.
Chances are you've read this information from an old video or from the unofficial Fandom wiki, which I do not maintain.

3. Sugar cane cannot be planted on Rich Soil without water.
4. Cacti cannot be planted on Rich Soil.

These are intended behaviors. Cactus should only be planted on sand, and Rich Soil does not benefit it, since it doesn't accept Bone Meal. Sugar Cane requires adjacent water to be planted, and Rich Soil (ideally) should not change that.

Sorry, I might have looked up an incorrect mod website.