There is an alternative approach for alive, territory and stone removal in territory scoring. This is NOT how current (J89) Japanese rules work (some others do), but is probably close to what they aim at, including seki, unsettled etc.
Instead of going from L/D → dame → seki → finally territory and stone removal, it can also work backwards. Territory are surrounded areas that can (with further imagined play starting with opponent) be cleaned up and taken pass-alive control of (without enabling compensation elsewhere). Then stones are removed if they are in the opponent’s territory, and that’s it. There is no need to define alive, seki, dame etc.