Hi Emeka,
In our case, all the above transactions were in the same month so, it shouldn't be an issue as regard to financial reporting.
The default for the reversing entry -"Mark as Return" is on the same date as the original problematic bank statement, but you can change it before you save. In doing so, it will not affect your previous month's financial statement. Moreover, if your previous month has been closed, I do not think that you can still post that Journal entries to that month. The reversing JE is a "Operational postings".
Hope this can clear your worries.
Regards,
Norine