I don't think Bradley really likes Lydia in that way- he just sees her as a friend and tbh I think if they did get together Lydia seems the type of girl who would get bored of him rather quickly.
Oh yeah- Bradley will deff feel hurt a lot more by Max than he will by Stacey. I think he will realise, and in a sense after his conversation with Max when he said he still loved Stacey he already knows, that he is partly to blame for the way she treats him.
But where Max is concerned Bradley has done nothing but try to get to know Max and give him chance after chance to rectify his past mistakes- for it all to be thrown back in his face! I tell you something I wish I was a character in Albert Square just so I could give that poor boy a hug because he's gonna need it! Yes he did treat Stacey harshly but he didn't deserve this!