Furthermore, if the selected set of delegates is short lived, then any disruption caused by selecting a dishonest nodes in the previous set will be minimal, as transactions that failed which are deemed legitimate can simply be re-presented a short time later against a new set of delegates.
The higher the frequency of delegate election, the worse the service they can provide - at one extreme, the service is completely trust based and very efficient and at the other extreme there is no advantage at all to having delegates but they are completely trustless.
I disagree, so long as there is a reliable method to allow everyone to know who the delegates are at any moment in time present or past, then selection could happen at 1 second intervals or less.