Hi there.

If it's a VFP Database then you can open it up in the vdp Database Designer and have a look at the RI and even the stored procedures.
U might want to check if columns referenced in the RI are Indexed for faster access especially when there are lookups.

Normaly Deleting RI might not give a problem if it is only to maintain RI and not update values in referencing tables. Maintaining RI can be done at the fron end also and so can be the updating. U have to take care that updates to tables other than the tables whose RI u want to delete are not referenced in the RI procedure.

Hope this helps.