Interesting. My only question is whether or not this is post Voldemort. I hope it is, it would nicely explain why Harry hasn't even thought of anybody from the Wizarding World. I think it is an interesting story idea with Harry trying to start over and have family and Clark having someone to understand and help him during the time when his powers are developing. I assume that since you stated Clark would be two years younger and Harry just turned 17 that Clark is in High School and this is at the beginning of the series.
More soon please.