Honestly my perspective is this:
Historically, Advanced Class Skills have been incredibly strong, so doing our Class Change as soon as possible is a pretty solid move.
If anyone here has read Rise, Song's Nemesis was the first one he unlocked, and it's basically a field that completely negates things that it touches. Physical force, magic, the works. At higher levels, he could use it to create a sensory field that spanned the entire world, rewind events across entire battlefields, and even exile people from reality itself. (Granted we never actually used that last option but we did take the perk.)
Now, I don't think our ACS is going to be quite that strong, as we're only a supporting character instead of the protagonist, but I'm certain it'll still be something incredible.
100, actually, our current cap.
100 is our global caps, yeah, but in our three speciality skills, our cap is 150 instead. (Martial Arts, Empathy and Supernatural.)
That's why we have MMA at 101 instead of 100, for instance.
That's his Bond level, his SL is at 4/10.
Hose Kohei:
Relationship 4/10 (8/10 Points)
Bond: Buddies: The two of you are friends. And friends help each other.
RP = Relationship Points, btw, that's probably the point of confusion. To be clear, I didn't mean that his SL was at 8, I meant his RP meter was at 8/10.
Basically, in order to advance a SL, you need RP up to the required amount, which in this case is 10. +1 gets it to 9/10, so we'd only need 1 more RP via whatever method in order to increase his SL with his action.
For Elizabeth, we're at 10/5 RP, so we don't need any more RP in her direction to advance her SL from 2 to 3.