You can specify a country in "Other parameters" - "Other metadata".

For the keywords iStock requires you to specify terms. You can do so in "Advanced editor" window using "Terms for iStock" button.
You can specify terms for groups of files at once. The program will also remember your choices for every keyword and use them for the same keywords automatically in the future.

There is no way to make iStock recognize keyword terms automatically from the uploaded files, you need the automatic submission feature.