I may check it out sometime, haha. My manga backlog is terrible right now. I want to catch up on Assassination Classroom, One-Punch Man, Beelzebub, and Berserk right now and I'm faaaaar from being done with that.
Releasing OSTs in BD/DVD volumes? Oh yeah. Happens all the time. In fact, it's probably more common than traditional soundtrack releases at this point. The difference is that the extra content in each volume is usually announced ahead of time, but that's not the case here.
Nah, I wish I owned them. It's the only series I've reread without owning the volumes prior. Most of the other series like One Piece or Rurouni Kenshin, I only really reread because I can pull a volume off my shelf and give it a read casually.
Biscuit Hammer is actually one of the few series I would say is pretty much perfect for me and it is a crime that it hasn't been translated into English yet. Yuuhi and Mikazuki's fight at the end was a perfect end to the series. Noi crying at the end really got to me. As did a lot of things in the series. Ludo. The mouse and mantis knight. Just everything I loved in that series. So much foreshadowing and whatnot, it was a pleasure rereading that series. Think it's the only one other than series I actually own that I have reread start to finish. My favourite knight? Could be the Dog Knight or the Horse Knight...although they all have their own quirks that make them great characters.