Cutting fucking sucks, but maintenance is easy.

My rules:
>weigh-in every morning
>lift 3x/week at least, to failure on non-compounds
>hit daily protein goal
People bitch at the daily weigh-ins, but if you do it every day, the weight can never "sneak up" on you, and you don't have to cut for too long if you fuck up and drink a gallon of deep fryer grease in a drunken haze.

>Is cardio a necessity?
No, but it's good for you and feels nice.