It isn't that Sven wrote country songs, it's that he wrote horrible, hackneyed country songs off his cuff that people over paid him for. He was openly contemptuous of the whole process, but not enough to turn down the buckets of money that they threw at him, apparently.
It really does seem that Faye is the first thing in Sven's life that hasn't just fallen into his lap. It's something he wants, and he hasn't just been handed it on a platter with little to no effort on his part. And I keep saying 'it' for a reason, because it's not really Faye he wants, but the idea of something he wants but can't have. According to the way he acts and what Dora has said in the past, he very much has a case of arrested development. He's never had to grow up. Now he's starting to. He has that same mentality of a 13 year old who's romantic knowledge is based on movies and is totally self-centered. So I really see this as being a learning and growing arc for him. He just needs someone, and Steve is apparently elected, to let him know that's not how life works.