I can't speak for how common it is but there is a more informal tasting for more of a general, personal appreciation rather than focusing on being analytical.
I guess you could say that.  Anyone can do it though, there's just usually a less analytical process for personal appreciation.
Is it true Wine tasting is a delicate art? I'm unaware if it is or not, but there have been scientific blinding wine tastings that contradict wine tasting reliability. What do you mean by reliability? I can't say but the purpose of the blinding tastings is for wine scientists exploring the human olfactory system on things like identifying the compounds of a wine's aroma. How exactly is wine tasting done? I don't have the exact steps but wine tasters use ever changing words to describe the characteristics of wine like its flavors and aromas. Sounds like a very niche hobby.
More informal, recreational tasting may use similar terminology, usually involving a much less analytical process for a more general, personal appreciation.