"A general question: If either question 1 or question 2 is NO, then doesn’t this cause potential problems in manipulating the input data and/or outputting reports"
Yes. And in several threads on this board they are talked about.
A point on transfering data.. "Mapping" is done even when the names are the same, it is the way data is transfered from one DB to another. So errors in "mapping" can occur, just because. some-one must write code that says "take data for here and put it there." That is mapping.
In two-way mapping they have to write mapping code twice. If data from DB1 "A" and "C" goes to DB2 "XX" Then DB2 "XX" is equal to the data from DB1 "A" followed by data from DB1 "C", Going from DB2 "XX" back to DB1, many programs have no way to know how to (or if they need to) split DB2 "XX" so it goes correctly into DB1 "A" and "C".
Does that make sense??
If DB1 has a data that DB2 does not have a place for, do the coders drop DB1 data -or- stuff it in a place somewhere in DB2 that was not ment for the data?
Who knows? This is a problem when two DBs are NOT the same and why "data mapping" (work that I have done for a living) is not easy and it is problematic