questions - can someone help?

Rating: Null/10 (23 July 2004)

**potential spoilers**
Every time Evan "traveled back in time", he ended up in the future in a substantially changed situation. Every time, that is, except (at least) once: in order to convince his god-fearing cellmate that he was "special", Evan traveled back in time and stabbed himself on each hand with vertical metal spires, thereby creating "jesus like" stigmata to appear on his hands.
Here's the question: Why is Evan still in prison? The prison scenario was the culmination of an idyllic life, albeit one in which Tommy became a maladjusted psychotic (more so than before). Wouldn't creating self-inflicted woulds lead Evan down another path, perhaps involving incarceration at Sunnyvale? It's hard to imagine why creating the self-inflicted wounds wouldn't have opened up another "timeline", as was true with every other future-altering juncture in Evan's past.
Another question is this: After young Evan gave Kayleigh's dad a verbal thrashing, Evan entered a timeline in which (1) Kayleigh grew up a happy woman, (2) Tommy became the embittered recipient of all abuse that he previously shared with Kayleigh, and (3) Evan became a frat guy. This is strange, because there was no indication that Evan's NOT being in a fraternity was the proximate result of the abuse he and Kayleigh endured at the hands of Kayleigh's dad.