Runner safe at 2B, but out for taking her foot off the base. How is that scored?
 

How would I score this... I have a runner on first and the batter bunts (attempts to sacrifice) and the catcher picks it up and immediately throws it to the second baseman where the runner is safe (standing), but her momentum put her over the base and it allowed her to take her foot off the base and the second baseman had her glove still on the runner and was called out by the tag. How would I rule the play? I initially the charged the batter as reaching first on a fielder choice and the runner is out 2-4. Would this be correct?

Seems right, but you really should check a coaching or general softball site, rather than an officiating site. Umpires don't get involved in scorekeeping.

I thought about saying this but since I'm kinda new here I didn't know the way umps viewed this.

I'll say this: if I did score, there would be a lot of players mad at me. I think they try to rule hit way too much. Not enough errors for errors that are made. I'm mainly speaking MLB of course but it is a trickle down effect as well

Not all umpires are afraid of dealing with a scorebook. ;)

This play could be scored as a SAC/FC for the batter. That's because the runner actually made it to second base before the throw. In essence, the batter did her job. The batter is not charged with an at bat in this situation.

Regarding the runner being out at second... Consider a batter trying to stretch a hit into a double. She slides and beats the throw but her momentum carries her past the bag. Credit her with a double and the out recorded outfielder to infielder. The outfielder is credited with an assist, just as if the runner had proceeded past second base, got caught in a rundown, and was eventually put out.

I object to that! I'm not afraid of dealing with the scorebook; I just have zero interest in doing so! :D

Since I am not an umpire and just an interested lurker...

By your description the runner reached 2B safely and then was tagged out. Hence, I believe the correct scoring is a sac bunt credited to the batter (since the runner achieved the next base) and then she is put out 4U (meaning 2nd baseman unassisted).

A device is yet to be invented that will measure my indifference to this remark. -- Hawkeye

I think it's call a black hole.