For AP and AR conversions, the associated GL (F0911Z1) records will not be the expense or revenue records. It will be the open AP or open AR account (like 1.1110.CON). I actually create in the COA lower level "conversion" accounts that allows posting and use these accounts as the associated GL records. At the same time, when you convert the General ledger, the balances of the open AP and Open AR accounts go into these conversion accounts. After running the Z-file process and posting the GL, AP and AR batches (if all goes well), you should have a zero balance in the "Conversion" accounts and the correct balances in the actual General Ledger AP and AR accounts. The integrity of the AP and AR accounts which have "M" in the posting edit code are good. After the conversions are complete, we inactivate the conversion accounts with "I". The only downside of converting this way: users will not be able to drill down on an open AP or AR record and see the actual GL side. But this is almost always acceptable.
COA:
1.1110 level 6 "M" -Open AR Trade
1.1110.CON level 7 " " Open AR Trade conversions
1.4110 level 6 "M" -Open AP Trade
1.4110.CON level 7 " " Open AP Trade conversions
The above can be made more complicated when there are more than one open AR and open AP accounts but I suggest you bring in a consultant who knows how to spec this out.
There is no z-file process to bring over Fixed Asset balances, only the Asset Master. I suggest read the oracle Support white papers on this. If you do not know how Fixed Assets work, I suggest finding a consultant who has done this. The white papers actually suggest this. Otherwise, you may be struggling for a long time.