I am very flexible, and will defer to you, as you are the head chieftan. As for House Blackfyre, according to the Wiki, there was supposedly more than one daughter that Maelys could have descended from. Again, your call, and I can change from Blackfyre to a bastard cadet house from Aerion Targaryen/Brightflame. (Though of course, I like the idea of being descendant from the Lady Blackfyre.)

As for Truth, the sword typically would go to the eldest, or the best fighter. But, as we saw with Samwell Tarly in the show, he took the sword from his family home, and the same could have happened for Maelys father. The main reason I gave him a sword, as his intention is to offer that sword in exchange for Blackfyre, the sword after which his family gets its name from. House Rogare was chosen as it has been on the decline since its patriarch foolishly declared himself Triarch for life. So for a third born son to strike off on his own, taking the family sword, and ditching his failing family behind isn't far fetched to me, but again, your call. 

Another sword is Poison I think... which is in the CK2 Game of Thrones Mod, belongs to House Vunatis, which were the lords of Bloodstone. But again, your final say. Let me know what you are ok with, and I will change from there. And if you stick by your guns, then I will make the changes, and scratch the sword, and present a revised character sheet.