Not all of them. Different Buffy comics have various storylines and timings. Some could fill in gaps from earlier seasons or offer alternate perspectives rather than strictly following after Season 7.
Not really. While there might be a few 'Buffy Suicide Fanfic' out there, they are not common. The Buffyverse is known for its action, magic, and complex characters. Most fanfic writers are interested in expanding on these elements rather than delving into such a distressing and controversial topic. Also, many fanfic communities have rules against writing about topics like suicide in a way that could be harmful or triggering.
Buffy began as a television show and only later was adapted into comics. So, it wasn't a comic initially. The TV series gained popularity before the comic adaptations came out.
Buffy's relationship with Spike in the comics varies. Sometimes they have significant interactions and may even be romantically involved, but it's not a constant throughout all the comic series.
Probably 'The Gatekeeper Trilogy'. It has been highly regarded among Buffy fans. It has a complex and engaging plot that unfolds across the three books. The trilogy really delves into the lore and magic of the Buffyverse, which is part of what makes it so popular.
Spike is often paired with Buffy in this type of fanfiction. Since they already had a complex relationship when Buffy was a slayer, it becomes even more interesting when she becomes a vampire. Angel is also a common pairing. Their past relationship and his own experience as a vampire with a soul add a lot of depth to the story.