1) Is rel_orders part of the m2mdata.dbc?
No it is not, it is a free table.

2) Does jomast.dbf have any memo fields in it? If so, it might make a difference to add MEMO to the SCATTER.
Yes it does have memo fields

3) Is gennotes in rel_orders (look like it is) and more importantly is gennotes a MEMO field?
Yes gennotes is a memo field.

4) Are the following ALL of the fields in gennotes?
- drawingnum
- fcustpono
- gennotes
- fgroup
- finumber
Im not sure I understand the question. Gennotes is a memofield that is the same as soitem.fdesc with carrige returns and extra spaces removed.

5) Does rel_orders have any field default values or triggers or other stored procedures that might act on it when INSERTed?
No not at all.

6) Is it correct that there are no later TABLEUPDATE()s or that TRANSACTIONS are in use?
That is correct, I just open it, zap it, append records and close it.
Should I be using tableupdate?