Data Integrity Issues

This is the first year we have been in a position to 'roll over' to a new year due to internal issues.  However as a result of starting a new company for every business year is over time you tend to accrue some errors that can not be easily traced or corrected with an adjustment in the corresponding journal.  Here is the issues I am trying to figure on how to fix as they relate to history that has been entered incorrectly.

1) For some reason my Vacation Payable account is way higher than what is actually owed to Employees.  I figured out how to unlink the Vacation Payable to make the change but not sure which account to Credit the correction to.
2) INVENTORY!!  For some reason there is large discrepancies between my Asset Accounts and the actual items in inventory.  Is there a way to correct this as I cannot just unlink these items.  

I admit I am not very familiar with this module or how it works and have no idea how this has occurred or how to prevent it from occurring again. Of course, the immediate issue is to be able to correct the values to match.

I appreciate any assistance with this as I am unable to do anything in the current year until this is resolved.