Are there any formations or features of the Grand Canyon that the "Carved by the Colorado River" Model doesn't explain well or at all? Is there anything that is "mysterious" under this model?
This isn't really my area of expertise, but ...
I don't know of any features the the CBTCR {grin} model does not explain. Many creationists don't much like the fact that the CBTCR model rquires that the Colorado Plateau be uplifted slowly, by plate tectonic processes, as the canyon is being carved. That is, the top of the canyon is crrently above the headwaters of the Colorado.
Also, do traditional scientist have any other ideas or models about the origin of the canyon besides the "Carved by the Colorado River" Model?
Not everyone agrees about some details or the exact timing, but there's no serious contendor for an alternate theory. The flood-runoff theory is a non-starter, even given the lack of evidence of the existence of such a flood at all. The near-vertical walls of the Grqand Canyon show that it was carved slowly while the rock was lithified (that is, hard), unlike the approximately 45 degree walls of the "Grand Canyon of the Toutle River" (carved by runoff after the Mt. St. Helens eruption, and often cited by creationists as "proof" that the Grand Canyon could have been carved quickly). See the pictures at the end of
Young-Earth Creationism and the Geology of the Grand Canyon: Part 2: The Grand Canyon. (Also the amount of material removed at the Toutle Rive is hundreds of thousands of times less than the amount of material removed to form the Grand Canyon). The pattern of the Grand Canyon and the Colorado River basin, with branched side-channels and several
180-degree turns, is totally unlike the pattern of flood runoff seen in the
Channeled Scablands.
Events in the Vicinity of the Grand Canyon of the Colorado River and
Evolution of the Colorado River and its Tributaries, including Formation of the Grand Canyon: Geologic History of the Grand Canyon present the mainstream theory pretty well.