Any more details on that Fuji conversation?
Steel is nice in that it can deform without breaking. I use an aluminium bike that has a beefy vertical rear dropout. But no off the shelf bikes have dropouts designed to handle the torque of a motor. If that motor spins in the dropout, it will destroy it (unless possibly it is steel).
I would rather get a better used steel bike off craig's list than a cheap one from a big box store. The components on those things scare me.