Currently, the Nouns Dao introduce a objection period where there is a last-minute proposal swing from defeated to successful, affording against voters more reaction time. 
This could be unfair to the for voters, where the reverse could happen, when there is a last-minute proposal swing from successful to defeated, but no time is allowed for for voters to react. Hence, protocol could introduce a new mechanism/state to allow this to happen, where similarly, only a against vote casted in the last minute voting block can trigger this period.
Currently, there are no mechanisms for voters to unvote or update their votes, and they can only ever vote once due to the hasVoted flag. Consider implementing a mechanism to unvote and/or update vote choice.
Queued proposals are still active, since it has not been executed. As such, consider not allowing creation of proposal when proposal state is queued. Given Nouns Dao only allow 1 active proposal per proposer, there could be a scenario where there are multiple proposals queued if proposals are not yet executed.
In the contest Docs, it is stated that any token holder can execute fork if fork threshold is met. However, anybody, not just token holders can execute fork via executeFork() once threshold is met. Since Nouns govern Noun DAO, consider only allowing only token holders to execute fork.
