Just my $0.02, to take or leave.
While some of our levels, like Monk and Initiate, do not of necessity suggest specific cultural roots, others, like Friar and Bishop, are, as far as I know, unique to the older Christian traditions (Catholicism in particular). For my part, I find it rather difficult to fathom someone finding this offensive. The metaphors I've seen employed here have virtually nothing to do with religion, but rather with reflection, study, and social hierarchy.
In fact, our present level titles have less religious significance that those footpad suggests. After all, titles such as Friar or Bishop have no metaphysical implications... I don't believe I've met anyone here who didn't believe that Friars or Bishops exist (Saints are a different matter). Totems, on the other hand, are emblems of spirits, not titles for people. If we're actually to worry about such things... and I suggest we don't... it would be a safer thing to have Imams, Shamans, Samani, Muezzins, Rabbis, Brahmins, Ayatollahs, Medicine Men, Muftis, Lamas (Dalai, Grand, Panchen and Plain Vanilla), et cetera.
In any case, if someone does find the current state of affairs or proposals for future changes offensive, they ought to post their views. The Chatterbox is no place for serious debate on site policy. I have never heard such a sentiment uttered even in the Chatterbox, however, so from my perspective none of this seems to be a real problem.
Aesthetically, I think it much more pleasing to keep to the established motif, rather than vary. Saint, to me, sounds like a excellent final level still, unless we'd like to append "Pope" at, say, 1,000,000 XP. Anyway, if we're going to bother adding new levels, I'd sooner raise the number of XPs required for Saint, and add lower levels. Of the many titles which would not break with the present theme my favorites are:
Of course, this would mean a lot of de-cannonized Saints, and perhaps some other shuffling besides. However there seems to be little difference between suddenly finding you're no longer a Saint, and suddenly finding you haven't achieved the highest possible level. Perhaps demoted Saints could be given a special title until they regain their former station... like Bodhisattva. Granted this doesn't quite fit the scheme, but the metaphor is nice: those who reached enlightenment and came back again. Whatever the case, one would hope that people would take it in stride, set their sights higher, and continue to learn, teach, and have fun as before.
Incidentally, I also like arturo's notion of honorifics... perhaps this whole thing shouldn't be quite so linear.