Honestly, he'd keep to the Sentai/Ranger convention of not using the Zords, or Megazord, unless there was a threat that merits it- IE, something just as big. The Zords are for proportionate response only. As for storage... this is one of many places Ninninger is weird. While they were in the Kamen Rider Drive universe for a spring break special/extended movie commercial, they were able to summon their Megazord to fight the monster of the week. I'd just say they chill around the hub world playing giant robot go fish or something.