So, they state that Bach is the only quincy who can give out power.... idk, it isn't like EVERY human associated with Ichigo got powered up just by being with him [/sarcasm] In fact, every person who has gotten close to Ichigo either received some form of power, or had their natrual growth accelerated; All the Shinigami who have been alive for hundreds of years, suddenly gain Ichigo's insain growth rate after meeting him?
So far, we assumed Ichigo received the Hollow from his mother during birth, but what if it wasn't like that? If she truly had given the entire Hollow to ichigo, she would no longer be an impure quincy, but if she hadn't passed all of it on, his sisters would have some, and Ishin wouldn't be able to leave the giga due to sealing the sisters. Bach already recalled all the quincy powers before she died, meaning the hollow wouldn't get sent to him after she died since she no longer had any link to him, however if Ichigo had the same form of link, when she died, he received the hollow. His linking souls with people, would also completely explain how he understands people he strikes blades with; he really is entering their soul.