If Christina Mani juggles any more plates, she would have to be an octopus to prevent a complete disaster. Either that or have a good broom nearby.The Benicia High School drama instructor has the Feb. 4 fundraising dinner, auction and musical showcase, “An Evening of Love,” in high gear while also rehearsing “The Music Man,” which opens in late March. Oh, and the school’s annual dance show gets kicking in a few weeks.