Why aren't we seeing carbon taxes in practice?
I think it’s mainly politics. For example, when France tried to implement increases in tax on  oil (indirect way of taxing carbon) it led to yellow jacket protest.


As you pointed out it’s easy to track who produces the carbon in the economy. Especially on industrial level in developed countries. The reason 1 could be problem in some developing countries though.
As you pointed out the revenue can offset any negative effect as with Pigovian taxes there is no deadweight loss - if set properly 
Again you answered yourself plus I would add in a long run it’s better to undergo temporary shock to avoid higher cost down hill.
I don’t think you can say it’s unfair. In fact I would say the fact that the industries create externality in the first place due to lack of property right is unfair (at least if we agree that creating externality is not fair to society which I think most moral thinkers would - although that’s question for philosophy SE).
You again answered yourself.


If you look at the attempts to introduce carbon taxes then you will see 6-8 are the main culprits. In France you get yellow jacket protests in Netherlands farmers protests, in Washington voters refused carbon taxes in referendum last year (see here)etc. - all responses to trying to introduce Pigovian taxes of one kind or another. People of any political affiliations generally don’t like taxes when they are taxes on them as well. I suppose many people also are skeptical the government will make it revenue neutral later by lets say sending check to all people so their income stays the same. In case of redistribution some might not like that and others also don’t believe social spending will increase.