update, just this week under Settings / Software Updates, at&t served up a 10.2 upgrade which i got some help installing. so far so good, and Delete on Handheld Only does seem to be back and working. (caveat, may have to delete one at a time from handheld while blackberry works out a glitch?) so far the update seems good. i have some abbreviated outlook contacts that don't seem, like before, to be synching to the q10 but will keep working to see if i can figure that out
KB35669-When deleting messages from the BlackBerry Hub, messages are deleted from both the BlackBerry Hub and the mail server even though the "Delete On" setting is set to "Handheld Only" or "Prompt"
UPDATE, this morning i tried deleting messages in a clump, rather than one at a time, from q10, and none deleted from my outlook account. hooray blackberry