Oh boy questions, lets see
1 & 2 - As i understand the first chapters focus on introducing us to the plot of the manga as the narrator recalls how it all began, but from that point onwards we follow the story in real time, so the narrator stops recalling things, and what used to be exposition bubbles become thought bubbles to see the inner monologue of the character
3, 4 & 6 - No idea, they all seem to be similar to found footage of stories, as if they wanted to portray the SCPs as parts of real events, since this manga has so far made no mention of any containment procedures, in this case the evidence was the manga diary of an author living in the country side, so maybe next chapter would be a podcast, or audio-logs for the research team (those are actually quite popular on SCP YT)
5 - no
7 - yes
8 - I also only have seen OP doing cover stories, but as i understood, what the editor asked them this time was to make a manga remake, a manga adaptation of another manga, in this case to redraw the manga diary that was found
9 - Something that has been notoriously absent so far, is containment procedures, which is the primary aspect of SCPs, you know SECURE, CONTAIN, PROTECT, yet so far no such things have been addressed, my guess is that the purpose of this manga is to be the containment procedure for the "real" ghost stories and urban legends that are being covered, by taking what looks to be evidence linked to, recalling, or mentioning a real supernatural event, and transforming it into a manga, the SCP becomes contained