I'm giving an example of a way to approach this problem. Installing Noscript could add a rule to an Adblock whitelist. What Noscript is doing by trying to sneak it in is wrong. If they wanted to overwrite a rule, let the user do it. As that article points out, and as Mozilla points out, making that the non-default option is very important.
No. Hell no. Antivirus programs conflict for a good technical reason. NoScript and AdBlock conflict because the author of one dislikes the effects of the other program; were it not for that, the two extensions would be completely compatible with one another. Equating these two things with each other completely misses the point.