I'm sure the moment you want to edit something, you'll have to throw money at M$.
No. Only premium functions, like creating a pivot table.
From Winsupersite:
More capabilities for consumers without Office 365
Regardless of which of the new Office versions—Office for Android tablets, Office for iPhone or Office for iPad—you're using, Microsoft has dramatically eased the restrictions for consumers who use the apps without Office 365. (Business users will still need Office 365 to use these apps, however.) That is, where Office for iPad previously only allowed basic document viewing capabilities without a subscription, now these new versions offer what Microsoft calls "core Office editing experiences" for free on each. To get access to premium editing features, however, you will still need an Office 365 subscription.
So what's the dividing line between "core" and "premium"? For the most part, premium editing features are those features that only business users would need. For example, in Word, you need a subscription to use Track Changes. In Excel, you can view pivot tablets without Office 365, but you need a subscription to edit or create a pivot table. In PowerPoint, you can create and edit presentations without Office 365, but Presenter view is a premium feature that requires a subscription.
"This is a pretty big shift for us," Lefebvre told me. "It should drive great usage and adoption."