Facts listing again! Not as much on this list as usual. As usual, contains spoilers.
As I believe I have previously noted - the Muei-tou (Shadowless Sword) is a spell devised as a counter to the Jigen-tou (Dimensional Sword). As a reminder, it functions by preventing anyone touching it from shifting between dimensions. It is not particularly strong on offense, but it serves well on defense. You can see what the Muei-tou looks like in the link below.
<a href='http://mangafox.me/manga/rosario_to_vampire_season_ii/v12/c055/17.html' target='_blank' rel='nofollow'>http://mangafox.me/manga/rosario_to_vampir...12/c055/17.html</a>
Kahlua apparently consistently wears the same dress (or perhaps just the same style of dress?) at almost all times. Even when doing housework (no matter how impractical it is to wear while cleaning the house).
Kurumu normally delivers Charm magic through her eyes, but Succubi can also cast Charm by kiss. It's possible for a kiss to transmit a Charm spell by accident.
Tsurara (Mizore's mother), as previously noted, has a lot of guns in her possession. One of the omakes shows that she considers a Gatling gun to be the ideal gun to carry if you need to be packing heat.
Kokoa can be easily baited with food.
Kokoa's bat, Nazo Koumori, generally stays polymorphed into that cute bat form. Its true form is supposedly a fair bit larger. Kokoa is aware that he's polymorphed, but has never seen his true form. We get a peek at... some sort of form in the link below this paragraph, but we can't say if that's his true form or not.
<a href='http://mangafox.me/manga/rosario_to_vampire_season_ii/v02/c008.5/4.html' target='_blank' rel='nofollow'>http://mangafox.me/manga/rosario_to_vampir...2/c008.5/4.html</a>
(Left yonkoma, third panel).
Kokoa doesn't really show it, but she notes that at 100 kg, Nazo Koumori is heavy enough that it makes her shoulders stiff carrying him around on her head.
Inner Moka believes that she needs to keep herself somewhat distant from anyone she would consider a friend so that she won't inevitably bring more trouble to them. She'd rather be alone than let anyone she cares about suffer for her sake. Thinking about it though, she seems to consider 'harsh training' or 'punishment' to be something entirely different from 'suffering'. Or perhaps the 'punishment' is supposed to be her way of keeping others at a distance?
Inner Moka is fluent in Chinese.
Alucard's defeat was ~200 years ago. During that fight, Akasha Bloodriver sealed herself and Alucard away, and she was not freed from that seal for nearly 170 years. The Shuzen family freed her then. Incidentally, this means that Tenmei Mikogami (the Headmaster of Youkai Academy) and Touhou Fuhai have to be well over 200. So is Akasha, but again, she's been sealed up for most of that time, so I doubt she was aging normally during that time. Though on that note, I don't recall if anything was stated about the natural lifespan of vampires in this setting.
Akasha fought with a sword when battling Alucard. She was wearing armour too (I'd say it's a bit overly stylish, myself). So it seems she isn't limited to bare-handed combat.
Akasha was apparently a Shinsou even before she fought Alucard.
Alucard's blood multiplies once injected into a person, gradually overtaking them and turning them into one of the many ghouls that later become embedded in Alucard's body.
Gyokuro Shuzen is an utter bitch. Should have been obvious before now, but this most recent chapter (most recent as of right now, at least) really drives it in.