Local foods, commodity flows, and margins

I've been asked to explore how IMPLAN can be used to explore value chains of conventional and local food systems. It may be asking too much of IMPLAN data, but I wanted to pass some questions forward. I'm using the attached graphic as a basis for my analysis, where the point of sale may be retail or direct to consumer/institutions. 1) Can I use the "IXI Input Output Accounts" detail to estimate both intermediary flows and direct sales to consumers, or do I need to use the "IXI Social Accounting Matrix", which does not have household demand entries? 2) Retail and wholesale requires margins, but am I correct that direct sales to consumers/institutions should not entail margins? 3) Can I use retail and wholesale margins to calculate the direct farm sales to retail and wholesale sectors using the "IXI Input Output Accounts" detail? 4) As exports of agricultural commodities have two channels by which they can leave the local economy (direct exports and exports of intermediaries (processors), do I need to make any adjustments to the export entry for each commodity to account for intermediary exports? (I realize that wholesale exports only account for the margins) 5) Just to make sure, are household expenditures in the "IXI Input Output Accounts" table only those purchases from local producers, or does it also entail purchases of imported items?