Carbon dioxide blocks a narrow spectrum of radiation. It acts a lot like food coloring dye mixed in water. If you mix in a couple of drops, the change is dramatic, but if you double it and mix in a couple more, the change is much less so.
If the only effect on the atmosphere was the CO2 greenhouse effect, and we added 10x the CO2 the average global temperature would only rise a couple of degrees.
The issue and the controversy that surrounds CO2 is how the Earth will respond to this added heat that it can't get rid of. If it's a tipping point, and will end up in a death spiral of factors compounding upon each other (ex. the permafrost melts and changes the albedo of the earth and that causes more warming, etc.) is where the science of climate change actually is.
The problem is that climate is complicated and no one can predict exactly how it will behave. This is why there are ton of models and it seems no one can agree upon how much the effect will be.
Climate skeptics will argue this is because the science done so far is mostly conjecture and very weak, and the conspiratorial among them will say that only studies that support climate change are being published/funded, so there is a lot of bias to make out that their evidence is stronger than it is. There has also been a lot of modifications to historical temperature readings, (this seems to be with good justification), but I personally can't judge.
Whether the effect of CO2 is going to be large or small is outside of both of our grasps, and we really have to trust on others to make that determination, unless you're willing to really learn the science behind it.
However, your list of reasons are just muddying the situation even further. They are easily debunked and if you proclaim them, and people find out they don't hold muster, you may drive people further into the climate change skeptic camp, which I don't think you really are trying to do.