Have you checked/searched Bing/Google/Apple Support Forums for info on the Pages problem? I think my first choice for Apple S/W problems is still the Support Forms, that's where there will probably be a whole forum just for Pages.
I contacted Apple Support as you suggested, who referred me to App support, who called within a few minutes. They said the dictation issue with Pages was known and they had put a priority on finding a work-around.
Meanwhile they suggested all the work-arounds I had already tried -- closing Pages, turning off and restarting the iPad, and even deleting and re-downloading a fresh copy. Lastly they recommended what we have been doing, dictating into Notes and pasting back into Pages.
Anyway the good news was that they called me back pretty quickly and that they know of the problem and are working on a fix. So I'll just wait for the little update-alert on the App store icon, and keep dictating into Notes for now.
Thanks!
Lorraine