There seem to be reasons to believe the earth is older than 6,000 years

Answer:

What you are saying is that you doubt God's power. If God is able to create an entire universe, why do you think it has to be done in a certain way or over a certain time period?

The Bible is God's book. In it, He says that it is the truth (John 17:17). One of the things He states is that the universe was created in six days. Those six days were at the beginning according to Jesus (Matthew 19:4). What you are contending is that the beginning occurred a very long time ago, leaving an extremely large period of time unaccounted for in the Bible.

The Grand Canyon

You make an assumption that you cannot prove. You assume that the Colorado River carved out the Grand Canyon using the same route and same flowrate that currently exists. First off, it isn't possible because the claim doesn't account for the side canyons, the missing material removed from the canyons, or the fact that the current river flow is unable to clear its own channel [Jon Albert, "Grand Canyon – The River Didn’t Do It," 27 August 2015]. There is a detailed article showing alternative explanations for how the Grand Canyon formed that actually match more of the evidence than the claim that the Colorado River carved the canyon. See When and How Did the Grand Canyon Form?

Rock Formation

Since God formed the world, it is natural to conclude that in that creation He formed rocks on the second and third days. Since you did not specify the types of rocks, let me point you to some articles that show solid rocks can be formed in short periods of time with the right conditions:

• Volcanic Ash Turns to Stone in Months
• Scientists Prove Limestone Can Form Quickly
• Opals Can Form in Weeks

There is evidence that the rocks found in the Grand Canyon were formed and then solidified (More Ground-Breaking Research Evolutionists Won’t Do).

Spiral Galaxies

You did not rule out the possibility that God formed some of the galaxies as spirals. But there are greater problems.

• "Furthermore, if spiral galaxies were billions of years old, their arms or bars would be severely twisted. Because they have maintained their shape, either the galaxies are young, or unknown physical phenomena are occurring within galaxies." [p. 34]
• "Computer simulations of the motions of spiral galaxies show them to be highly unstable; they should completely change their shape in only a small fraction of the universe's assumed evolutionary age." [p. 41]
• Spiral galaxies at vastly different distances (from 2 to 106 million light-years) have roughly the same amount of twist in their arms. Further galaxies would not have as much time to rotate and twist as closer galaxies since light would take longer to travel from the distant galaxies. Further galaxies should be seen as further back in time. This near equal twisting, regardless of time, should not be possible if the galaxies evolved. [p. 325]

[Walt Brown, In the Beginning: Compelling Evidence for Creation and the Flood, Center for Scientific Creation, 2008].

Expanding Universe

You are making an assumption that you know the starting condition for the universe. It does appear to be expanding currently, but from what starting point?

If the universe started from a single point, as the Big Bang Theory suggests, the expansion should be slowing down. However, the red-shift indicates an accelerating expansion.

Stars in the outer parts of spiral galaxies are moving much faster than physical laws say they should.

"It is widely recognized that gravity would not pull matter into long strings of hundreds or thousands of galaxies -- even if the universe were unbelievably old. Instead, gravity, if acting over enormous time and distances, would form more spherical globs of matter. Yet, long, massive filaments of galaxies have been discovered." [Walt Brown, In the Beginning: Compelling Evidence for Creation and the Flood, Center for Scientific Creation, 2008, p. 329].