Hi. Bobcat:
I'm sorry, but I can't answer your question definitively. I see two problems here. First, there are two parables under consideration. The one about keeping watch which is what Peter is concerned about, and second, the identity of the FDS as mentioned in vs 42. Does everyone, including unbelievers, have the responsibility to keep on the watch or is that exclusive to believers? That is what Peter wants to know.
To complicate matters, Jesus does not answer Peter directly but adds another parable, that of the FDS, asking, "Who then is the FDS...."
The second problem is determining the appropriate antecedent to verse 48. Is the part about "much is given" refer to all those willing to be on the watch, or to the FDS"? I don't know. I can only quote from a commentary I used back in the 50s when I was in school. Published in 1920 and written by W. Walsham How, it says:
"Our Lord does not answer this inquiry one way or other , but continues his discourse, leaving the Apostle to draw his own conclusion. That conclusion would be, that the lesson is for all, but for each according to the work entrusted to him by the great Master"