Miracles, IMO, are both rare and powerful.
If we look at what a holy man should be able to do on a regular basis, it should be limited to rites and rituals, which should have a profound effect without being at all miraculous -- boosting followers' morale, boosting Will saves, replenishing intangible plot-protection points, etc.
Miracles, on the other hand, are clearly not under the direct control of a typical holy man, and they're certainly not available n times per day, affecting a radius of i feet, etc. They seem like the should come into play only at higher levels, or when thematically appropriate, and the player should only suggest what kind of miracle might help; what actually happens should be something of a surprise.
That's basically what I'm shooting at. I'm basically with you guys.
Rites and Rituals would be more or less under the Cleric's complete control. They could be performed as they wish, whenever and under the appropriate circumstances, though they could still be disrupted.
Wonders they could do on most occasions, they would be granted authority by their deity to do them, and they would have some control over them, but not full control. It might not turn out as expected though. They set out to cure critical wounds and because of some other considerations they only end up curing light wounds. Maybe curing nothing. On the other hand, if they have followers with strong faith, or they were being particularly rewarded for excellent service, had great faith themselves, or similar considerations existed then they might end up just plain curing all injuries on a person. Even old ones.
Miracles though, the cleric might desire to be a conduit for in a particular situation, but for whatever reason or reasons he isn't. Or he might become a conduit for some miracle when he's not even attempting to be or it might catch him completely off-guard. Miracles may be desired, but they are unpredictable and unregulated. And their effects cannot be anticipated.
A cleric (then again anyone else could as well, it's just that clerics are more naturally so) would be associated with miracles, would even try and promote and encourage them, but could not control them.
And I agree very much with the idea that true miracles (versus Wonders) should be very rare and very powerful. They should stop people in their tracks and make them go, "Whoa,
that was truly miraculous!"
In my opinion the good cleric should not take credit for Miracles, but he or she should be able to say, "See,
I told you so."