Seems like voice casting was a bit odd for some of the roles, I would agree.That's funny I just rewatched that a couple weeks back. Felt they were wrong to give Maki a super high pitched child voice. =P
For runtime, the JP LD lists 45 minutes on the sleeve and runs slightly over 46, counting credits. The ADV 50 min runtime seems to just be including the post-credits "production portfolio" material. Should be slightly longer than 50 mins as the production stuff goes on for 7 minutes but I guess they just rounded down both that and the general runtime to get a"clean" number. Prob where all the discrepancies are coming from.
I have never seen any of the spin-offs but from a biased perspective...they really don't look very good. Not sure how you could go from:
To this... (Burn up! W)