I was with you up until your last sentence. My partner identifies as vegan and has done for more than a decade. By way of background, she has a PhD in animal ethics and has worked as an ethicist for research institutions. She and her vegan friends have no problem eating bivalves: mussels, oysters, abalone. There seems to be widespread agreement among vegans that they're about as sentient as a flower. I'm very happy to agree. *Edit: Updated the link because the DFW article is such a good read I decided it deserved its own Hubski entry.
Yes I threw that in to be intentionally provocative. The lobster obviously has a nervous system. It lacks, however, anything like the pain processing and memory mechanisms that mammals and birds possess. I shall respond more fully after reading your link.