The easiest way is probably to use one of the tools available for data comparisons such as Apex SQL Diff, Red Gate SQL Data Compare, or xSQL Data Compare, etc (I'm sure there are others).
But if you don't want to shell out for one of those, then you should be able to write a script to disable all the triggers, constraints, etc then SET IDENTITY_INSERT ON a table, insert all the records, set it back off, and then move to the next table.
I don't mean to beat an already-dead-horse, but I just didn't see what the huge objection to calling it disabling an identity was. Did you find some documentation on "The reason M$ used IDENTITY_INSERT ON instead of DISABLE_IDENTITY" ? Please don't take my responses as hostile; this is a friendly discussion on semantics.