Personally, I wouldn't sweat a BK account not showing a specific 'closed' dated. Quite a few of mine don't have a specific closed date and no FICO score analysis is indicating any problem due to that. Now, if a reported 'closed' date is AFTER your the date BK was filed, that could adversely affect your credit score.
Check if the account in question is considered closed on your credit reports from here at MyFICO under the 'Accounts' heading. Also, make sure no post-BK lates are reported.
As for the balance on a BK account being reported as "0" vs. "Not Reported," there has been some debate here if it matters in the scoring formula. I'm of the mind that it doesn't matter, as long as there is no past due amount showing.
I've found the most hurtful things once an account is in 'BK' status are...
1. to have post-BK payments reported on an account you are still paying. (A mortgage in my case.)
2. to have "Bankruptcy" in the comment line of an account. Without the "Bankruptcy" comment, a 'BK' status account is neutral. With the "Bankruptcy" comment, the account is a negative. CRAs often add this comment when they get their mitts on your BK papers.