I am following the Physics Q&A site for active researchers, academics and students.
How can I vote for example questions being on/off-topic or ask an example question myself?
Since Physics is already in the commitment-phase, the definition-phase is over and nothing can be changed there any more. However, this does not mean that the site is shaped for good, as soon as the beta starts the committed users will have 7 days on private beta to give example questions and discuss basic matters more detailed on the beta meta.
You can however still ask and vote on example questions at the Popular Natural Sciences proposal which is intended as an interdisciplinary supplement on a more basic level, and there are also a High Energy Physics, a Biology and a Chemistry proposal in definition-phase.