I used qhero, I let qhero pick the keywords. it makes everything easy. otherwise I would not submit to istock.
I have given up on submitting video to istock. lucky I got a lot of videos submitted before they added the keyword disambiguation, so I make some decent money from my old material.
when I used the manual term selection, istock was making all of my images have the same terms. so why even have keywords if the unique keywords are always rejected?