Draconic summoning (rather than teleportation) is explained by the Bel-Zahkrii summoning spell of base Feat Heraldry and Ordained Heraldry, along with the Azdrazi's capability; it is essentially soul-binding of a weapon (without a scabbard) and quite literally places the item into a soul armory, though in this case the scabbard is the "armory" and therefore multiples can't be bound.
This sword can always be summoned no matter the area or plane of existence so long you have the scabbard. There is no limitation to it, because the scabbard is explained as the vessel in which the item is bound. In effect, it is the same as draan-binding but ONLY for dracanium weapons. While a dracanium weapon may have a dracanium hilt and a blade of some other kind, Draconic runes in all areas still function regardless of planes of existence, against thanhium, other magics, etcetera; there is no way to staunch it, as it's bound through the inscription itself. Theoretically you could damage the rune, or do what is described in the redlines (destroy the scabbard) and it would in thus also destroy the weapon if the weapon is not presently summoned into reality.
I suppose you could argue that the sword is not summonable between realms if it is left behind, but I would beg to see anyone try to do this ... it'd probably and hopefully be stopped by the ST overseeing this dimension change. Likewise would this apply to draan-binding. I would have to talk to Kalehart about that one (and they're welcome to encourage the redline if they think it'd be good) but if I add it here, it'd need to be added onto heraldry magic as well. Not sure how that works so I'll wait.
Nothing. As this lore is based off of inscription of Ordained Heraldry, nothing can stop the rune except physically damaging it. There is another rune in Ordained Heraldry called Dratho-Zha -- which is a defensive enchantment. The only thing that can break the rune is disconnecting the rune's contact with the second. In effect, you have very physical ways to destroy these runes, rather than magical methods. This allows for anyone and everyone to break these runes without necessitation of acquiring further magics or ST-signed materials. Logically, a paladin's weapons might instantaneously destroy a rune per discretion of the ST if it is a significant lore item, but otherwise magic will not impact them unless described.
Cursing? I don't know, I honestly know very little about shamanistic magics. I do know the previous rewrite mentioned hex-warding but I removed it merely out of my own sheer ignorance of shamanism.
Specifically it won't knock those back and anything larger. I don't want to apply a weight because then humans, dwarves, etc will argue their giant armored suit they should probably not be moving in will not knock them back. I would say it won't knock back anything over the weight of 500-600lbs but it's just too technical to start getting into that. Really, it's just a knock-up for people and I want to avoid it being used against structures and large monsters because if it isn't listed, it can be abused. I reckon if anyone has trouble figuring out if something can't be knocked back, an SReq could solve the problem with a quick verdict.
Will fix, thank you!