As for the nurse crop, 2 years might be overkill. Just plant it as you originally planned, and then overseed just the plants that you seem to be lacking as the plot matures. If it is sparse on burnet, add more. Need some more chicory, throw some down. 2 years of red clover and you might just have a red clover plot, it can be very aggressive on good soils in the right conditions.
I personally wouldn't add the red clover...unless a red clover plot is what you want long term.
Will do! No red clover!