doubletap won't do the job systemwide, think about microb, it zooms on doubletap. I still think the only place remaining is power menu.

BTW HIM plugins might export (and some of them do) a function to get its description, look in CSSU gitorious (hildon-input-method-plugins) for the name of the function and result format. In description there is a name you can use to fill your list.

There is an ongoing effort to bring the full portrait support to stock VKB, look at http://talk.maemo.org/showthread.php?t=79899 if you still haven't done