That is good not bad because makes the quest better. It gives AbyssalDivine more material and it will be of no consequence. It will be either interesting for him to learn as he goes or it will not matter. It is not like he is going to have that much difficulty since the technology is easy to learn. He is not going to learn about the supernatural on the internet.
If it was of no consequence or if Abyssal didn't want to write it, I'm pretty sure Abyssal wouldn't have included it as a dedicated option to spend time on. I will point out that Youtube wasn't a thing during the 5th HGW, and nor was Twitter. Even just having a rudimentary understanding of social media would be helpful for Shirou.
What is of actual consequence is building trust with Sae. We should start now. This is going to be when she will pay the most attention to him since he just got to her home.
However, I do agree that building trust with Sae is going to be easiest before the Phantom Thief business starts in earnest. So I wouldn't be upset if spending time with Sae won.
This is not a morally flexible Shirou and he was raised by a magus. I am not sure how comfortable hhe would be with changing people by force through supernatural means.
Not in the sense of changing their minds. In the sense of slaying their inner demons so they have a choice about whether to be a dick or not.
Remember Shirou went from trying to talk peace to killing Shinji in no time flat. He would be quite happy to have the option to beat up their daddy issues or something so they reconsider their lives
This.
Fate Shirou is idealistic, but he's not naive or delusional. If the Phantom Thieves were outright brainwashing people, then Shirou would probably have issues with that, but considering Morgana explains how the Palaces work, I think he'd be okay with it. Also, Ryuji and Joker initially hesitate going through with Morgana's plan when they learn it could potentially kill Kamoshida, but I think Shirou would be considerably less hesitant about going through with it, consider he has Angry Mango egging him on, as well as his own experiences in the HGW.
Shirou is a very straight laced good guy. He is not rebellious and would not style himself as a thief. He is not that kind of hero that rebels against society. He is not a non conformist. That clashes a lot with the themes of Persona 5.
While I agree that Shirou's metaverse outfit would not be styled after a Phantom Thief like Joker, saying that Shirou isn't a non-conformist and that he wouldn't rebel against society is a very limited view on his beliefs? Like, EMIYA's existence absolutely disproves this, having died trying to stop a war by fighting against both sides. Shirou's ideals have nothing to do with laws or society, and everything about protecting others. If Shirou believes he cannot protect someone by working within the confines of the law, he absolutely would step over them as long as the actions didn't conflict with his actual morality. He and Makoto share a lot in that regard, except that Shirou has already gone through a bunch of character development towards refining his ideals into something healthy.