"They are not coming home today."
Translation:Hawaji nyumbani leo.
I'd say yes. Someone might argue that there's no "back" in the English sentence, but if it's "home" they've clearly been there before, so if -rudi is the most natural verb in this situation, I'd say it's right.
In the negative sense (i.e. when it is "i do not" instead of "i do"), you drop the 'ku' at the beginning of all verbs. In the positive, you keep the 'ku' if it is a one-syllable verb