Well argued.
Yes, the power you described is indeed clerical spellcasting.
OTOH, the power swap feats don't let you have anything from the "At Will category," nor anything from the (as yet non-existent) non-Attack category of Clerical Prayers. Should something like that be added to the game, PC's will need to burn more feats.
But Channel Divinity is not the be-all and end-all of devotion to a diety.
Perhaps its a matter of flavor- in a realm where
everyone has powers and so forth, a cleric who can't Channel Divine sounds gimpy & non-Clericy to me. He can't be a direct conduit for his god's will like all the real clerics can.
If you're a Christian (or understand its heirarchies,) to me its like the difference between a priest and a deacon. Depending upon denomination, a deacon can do a little or a lot of what the priest can, but regardless of denomination, he can't do it all.
Well, that's not quite right - you can pick prayers up after the fact with the later power swap feats (and paragon multiclassing or hopping to a cross-class paragon path.)
That PC was a front-line fighter who eventually became the sole source of Turning, etc. in the party, without stepping away from the front. That PC can't be done in 4Ed without seriously altering the sequence of character development because the multiclassing feat doesn't grant the requisite abilities.
As a matter of fact, nil.
Nobody in my various groups- myself included- thinks much of 4Ed.
What feels like the defining characteristic of the leader role classes in actual play is *definitely* the minor action healing power, not the channel divinity stuff. We use all of those up in almost every fight. They're hugely important, much more so than second wind or the channel divinity powers, I would say.
Perhaps from a mechanical point, but the flavor is quite off. And off-putting.