thom,
I usually suggest the singular name for BOs: Account, Worksheet. This will come in handy with some of the automatic configuration that happens with AwareIM.
A couple of tangent questions for you:
1) Is Account a member of the SystemUser group? This is significant because if Account IS in the SystemUser group, it is ALWAYS in context by using LoggedInAccount...
2) Can a Worksheet be related to more than one Account? If not, I suggest that Worksheet be owned by Account.
Now re: "my logic goes something like this..."
IF Worksheet EXISTS WHERE(Worksheet.AccountFW=Account) THEN
FIND Worksheet WHERE(Worksheet.AccountFW=Account)
EDIT Worksheet WHERE Worksheet.AccountFW=Account
ELSE
ENTER NEW Worksheet.AccountFW=Account USING WkshMain
Adding the bold section should make the "Select Process Input" prompt go away. Without the FIND, AwareIM has not idea which Worksheet you are trying to edit, so it asks you to choose one.
Tom