If you have submitted an allocation via either a batch file or on-line to the Registry, can you go back in and edit the From/To data?  How about editing other submitted SAF/OAF data?
The From/To field is a key ‘header’ field and therefore is not editable once it has been submitted.  You would have to do a full form replacement should you wish to amend this data.
 
Also, other key or ‘header’ data (i.e. product, activity, from/to, cascade from, etc) cannot be edited after it is submitted, however, the detail information (stream ID /owner ID and factor or volume data) can be changed/modified.

Can you clarify the use of 'ALL' in the From/To field for allocations?
The use of ALL in the "from/to" field allows users to report an allocation of all volumes at the gas plant, regardless of where it was delivered.  Some operators do not track the specific well(s) that delivered to each meter station, but rather the volume applicable to each owner.  At the gas plant, the operator is aware of how much volume is attributed to each well and owner but they do not track the well level beyond that point.  The use of ALL provides the operator with the ability to report the allocation of the gas to streams and owners for all "volumes available for sale", without having to identify the specific destinations.

Do I always have to match the product reported in volumetrics on my allocation or does the Registry have product groupings in allocations similar to those used for product balancing in volumetrics?
The Registry does have product groupings that balance different products together. For allocations, if the product reported is a group (e.g. Oil at batteries or C5-SP at gas plants) and no other allocations for products in that group are submitted the Registry, the Registry will use the group allocation for all applicable products.  For example, at a battery an allocation for the product “oil” will also include “condensate” and “C5-SP” - if there are no allocations submitted for these specific products. For a complete listing of the product grouping used in the Registry see Edit/Validation Rules Related to Volumetric Data Submissions in the Petroleum Registry of Alberta document.  This document can be found on the Registry website: Bulletin Board – Documents – Reference Material

Do I have to cascade back from GS on an SAF and then do SAF/OAF at battery level?
It is not mandatory for operators to submit a SAF at the GS and then respond to the cascade at the battery level. Operators can submit the SAF/OAF for the GS, allocating directly to the well/owner level, if they know the streams/owners. 
 
Operators only need to report a cascade if they don't know the lowest level of reporting (i.e. they only know what facilities to allocate to, but not the wells, units, or well groups).