I’d have to review to make sure Jim didn’t nerf starting points but off the top of my head there were bonuses the guide reviews for having owned the previous game and purchased the bonus points for the current game. I forget if I am missing something there.
Edit: there are also skill point bonuses for tougher challenges also broken down in the guide. There may be some tweaks or new things Jim added, I have yet to check so let me know if you find anything missing!
In Part 2 or Part 3? In part 2 he always refuses (but in the code, he is happy that you asked him). In Part 3, if he is asked (after the museum fight, if he survives and you freed the prisoners), he will join up, and gel really (surprisingly) well with the group.
try looking a detailed zombie sample guide that’s the key element. Along with high science and medicine, but you don’t need to choose the scientist background to do it.