1. So by your definition the mechanical rider is not a rider as she costs 12ss?
😛
2. I haven't faced Misaki so I can't truly judge this, though I think Misaki wave 5 initially was a bit over the top (though I won't argue that there aren't a lot of really strong stuff out there, looking at you nicodem with your stable of kentauroi). I think it is still very strong, and I also think she is designed as a very risky very aggressive model and I think that is represented well in how she's turned out.
3. Kentauroi are very good, don't get me wrong, but how are they riderlike (wk6, cg10 ?, cause the lone marshal and mounted guard also have this, it is quite general for mounted models) since they lack the scaling mechanic. And they're definitely no yasunori :).