Nonsense. We can date lava that's been out of the smokehole for 200 years (per historical records) and see radiometric dating methods give us ages for it of tens of millions of years. Evolutionists rely on these methods because they give them the numbers they want.
2. Even if all radiometric dating were invalid -- again it isn't -- radiometric dating isn't essential for proving either that the earth is more than 6000 years old, or that evolution takes place.
Concerning the age of the earth, how so? Concerning biological evolution, it's largely irrelevant for directly addressing that question.
Whoever is feeding you your information is doing a notably poor job.
Ah yes, the old "poisoning the well" pseudo-argument that evolutionists like to slip in. I guess I should just respond by noting that evolutionists suffer from group autism, and refuse to allow anything to intrude upon their self-contained fact-space, thus disturbing their cone of silence? Just as good of an "argument" as yours.
If by "we" you mean young earth creationists, you're right. However, scientists don't make the same mistakes.
In the case I'm familiar with, a creationist
1. Applied the wrong kind of dating to the wrong kind of rock (you can't apply K-Ar dating to rocks with little-to-no Potassium).
2. Failed to remove xenoliths from the rock being examined (causing contamination of the sample)
The validity of every radiometric dating technique has been repeatedly confirmed by other dating schemes.
Concerning the age of the earth, how so?
Are you kidding me? Tree rings go back farther than 10,000 years. Varves go back 13,000 years. Ice cores go back 800,000 years. All go back more than 6000 years, invalidating creationism.
But don't stop there. Plate tectonics and palaeomagnetism can be used to derive rough ages of the earth (even if not as accurate as radiometric dating). Helioseismic dating accurately confirms the date of the sun (which, according to a Creationist interpretation of the Bible happened on the same day as the creation of the earth). Mitochondrial mutation rates date life back hundreds of millions of years, not a direct date for the earth but certainly an indirect one. This is just stuff I'm pulling off the top of my head -- I'm sure if I actually thought longer about this I could come up with many more evidences for an old earth.