It's a good list.
I'd add
1b) Udajima's connections
Udajima talked to someone in Zegelt city. Udajima has a lot to gain from getting rid of Akira. Maybe his allies do too.
5b) Tiol
Tiol was the one making Akira fakes before. Though this seems a bit sophisticated for him.
7a) Nationalists
Akira has thwarted them a few times.
7b) One of the Big Five
Whichever competitor was messing with the Sakashita transport may want to get rid of Akira too.
7c) Carol's enemies
She hired a bodyguard because she was scared. We may not have met the scariest people after her yet.
7d) Alpha's enemies
Most people have not figured out the connection between Alpha and Akira, but if someone did, they might want to thwart her. The method seems indirect but maybe it's less traceable that way.
I have a feeling it will turn out to be a combination of interest. Like Udajima plus one of the Big Five, or Mizuha plus Nationalists, or an AI and one of the hunter groups. For the plan to go smoothly it helps to have both city connections and people who can take shady action.
I wonder who cares about the Kuzusuhara depths. There must be vested interests for and against exploring them. As readers we don't have a lot of information about the politics of that. It seems like it is a big deal if the Big Five are fighting each other over it.