Hello Christiana,
Chambers also defines vivid as "full of life", that was how I justified the entry at 24d. I am also baffled by the 4, albeit completed, unclued entries, so can offer no guidance at all on those. When it comes to subjects historical or classical I am an absolute Philistine! Given my age history seems to also include remembering why I went upstairs for something!!
Hope you shake off the family inflicted illness quickly, perhaps you should tell your son if he does that again you will disinherit him!!
Finally I would like to wish all the EV N&C Wine Clubbers a Happy, Peaceful and Prosperous New Year. Sorry, but I don't have any cards to post here!