Tax/loot collector

A builder (free) can be set to collect a portion of loot in the morning, but since tax collectors are greedy, the longer you wait the more he'll "lose" (keep for himself). It could possibly even be that if that builder is attacked you'd get small amounts of loot.
The tax collector could either toll villagers, or the drills, mines, pumps.

This would kill the economy and collector raids, so I don't see this happening.

Economy would get destroyed if this happened. Builders should just do what they do...they don't need to be involved in any loot ideas honestly.. they should just be builders is all.