Try setting the following if you want buildings to decay normally:
"twigMultiplier": 1.0,
"woodMultiplier": 1.0,
"stoneMultiplier": 1.0,
"sheetMultiplier": 1.0,
"armoredMultiplier": 1.0,
Anything else in the config you can set to 0.0 to disable decay for that type or 1.0 to enable normal decay. If you want things to decay faster than normal, set a number higher than 1.0.
To protect entities in range of a TC, you will need to set:
"requireCupboard": true,
"cupboardCheckEntity": true,
"cupboardRange": 30.0,
Adjust the range as you wish, but it can also tend to overlap cupboards in range of your neighbors depending on how far away they are if you set it too high. Hopefully this is close to what you're requesting.