Coronavirus capsid missing?
Does it really contain a capsid?


Yes. Coronaviruses have a capsid, but it's not reminiscent of the polygonal (icosahedral) capsid depicted in the Research Gate picture you referenced. Icosahedral capsids form a sort of shell around the viral genome, where helical capsids actually bind the viral nucleic acids, holding them in a more rigid shape. 


  Is it SARS-CoV2 lacking a capsid, and thus special exception from general description of coronavirus?


SARS-CoV-2 is not an exception. In fact, its nucleocapsid is a target for diagnostic tests. 


  What is the actual/ realistic shape of coronavirus capsid?


It is actually depicted in Goodsell animation you referenced. The nucleocapsid proteins are the squigly bits in and around the genomic RNA (labeled "N", for Nucleocapsid). The actual capsid is the complete complex of N proteins bound to genomic RNA, so it doesn't have that polygonal outline that maybe we're used to when we see depictions of viruses. If you want a more detailed look at the actual capsid protein structure, there's a depiction of its crystal structure in this New York Times piece co-authored by Carl Zimmer.