Re: Agile?
It can't go wrong as long as you embrace the Agile principles because the definition of "not wrong" is embedded in these principles (wheter that's good or bad is another discussion) And nowhere in those principles says that Agile is adequate for fixed cost/fixed schedule projects that have no scope defined down to the precise wording and layout of documents and UI and precise specs of business processes. Which is something I haven't seen in any project in the last 35 years.
I don't want to sound smug, but I cannot think of any methodology that accepts changes in cost and scope without assuming schedule or budget changes that can possibly work.