There are a few proposals that I wanted to help with questions without following as the subject itself is of no interest to me, yet I feel capable to help. Voting might be considered more controversial, as I would help to form the page (adding 1/20 to a possible acceptance of a question as good example for on or off topic).
Yet the questions submitted in the first phase do not prominently show up in the beta site. Try finding the off topic questions in WebApps - I was not able to.
Therefore I think that in the beta phase the page will be shaped and formed to its at least temporary final domain, which means that even voting on questions at most will give a temporarily wrong picture of the path the site is heading. Yet comments and the gang of followers can easily outweigh the few votes and questions received by non followers.
Therefore I only see a problem if the majority of question posters and voters do not follow and that causes your site to divert heavily from its stated purpose. Then maybe moderators are willing to help.
Of course, your concern is more in how to collect all the followers that you need to proceed. ell, you don't, you only need 5+5 questions. After that you need committed people. And I made myself only follow proposals I will most assuredly commit to afterwards.
So, in short, I guess it is no problem to vote and post questions to pages one does not follow.