I would do any combination of or all of the first four, utilizing methods to ensure the core characters involved were active, interested, and skilled RPers willing to work with staff to make sure the plot was interesting and reasonably easy to join by others on the muck.

If this failed, starting a new storyline from scratch would be my backup plan. It's an unattractive option to completely nuke everything and start over with all characters and the plot itself being reset to another time period and backdrop, but if necessary to break out of the current RP rut, I would do it.

On both fronts I would support the creation of RP guilds within the muck for different types and skill levels of RP, and though outwardly it might seem a bit clique-ish, I feel it may be necessary and even beneficial with close wizard regulation. However, as an aside I believe certain wiz-sponsored TPs or globally-open RPs should be implemented to maintain global coherence.

An example of this would be a guild for feral creatures, where those who are willing to play or spoof ferals can take part in special sub-plots involving only fellow-ferals, but with some RPs and such being open to all types of character, or perhaps a team-up with another guild to create dynamic meetings amongst groups which are themselves more dynamic and fleshed out than if the guilds had not existed.

Just some thoughts...

I like all the options hopefully we can do something soon