Points in the paint is probably not at all doable since I don't know how you'd identify that, but it would still be nice to have for funsies.
Not possible there is no indication anywhere in the play-by-play source about where the shots is taken from or the distance. You only have the type of shot: 3 pointer, fade away, driving layup, jump shot, dunk, alley hoop etc.
I think second chance shots is doable because after a missed shot, if possession doesn't change, the next shot is a second chance shot.
it requires a lot of fiddling because:
1) you need an offensive rebound
2) the same player who got the rebound needs to shoot the ball in the next few seconds
It's not as simple as: "possession doesn't change", because the game has those genius rebounds out of bounds and also contested balls which don't change who has possession of the ball. Also you need to rule out all the situations when a player passes the ball after the offensive rebound, which is the tricky part (because the same guy can take the shot after several passes have been made and 20 seconds have gone by).
On these, I wasn't suggesting user-created tools, more of a wish list of things I wish were available in the actual box score/live viewer. I don't even know if points in the paint would be possible with the current engine, because I'm not sure how accurate the position of shots being taken actually is (if the position is calculated and displayed correctly in the viewer, it would be possible but I expect that's not very precise).
Second chance points is a team stat. Basically, if the team misses a shot (and isn't fouled), but retains possession, any points they then score before losing possession are second-chance points. It'd be something that can be useful at a glance to see how much rebounding is helping or hurting a team in a given match - if you hold a team to 25% shooting but they rebound half of their misses then they'll have roughly 50% effective shooting per possession (at least, on possessions they don't have a turnover).