Today's PR0 links are tomorrow PR8 You never know. Get links and forget about PR, it'll grow as time moves on.
It's better to have PR0 backlinks than nothing at all. Yes it will increase your pr if you have PR0 as of the moment.
PR 0 backlinks will help your site to improve search results ranking but not as much as backlinks from high PR pages will.
Don't worry about their pr but focus on thier quality. Theme related links are always better even if they are 0. Good Luck!
It all depends on what site the PR0 is on. I would take a PR0 from a well established, authoritative site (if the link page gets spidered) over a PR3 from a fairly new site. And it's true that eventually those links are going to gain PR and mature (at least you hope they will : )
PR0 backlinks are NOT really PR0. If the page the link is on is indexed in google, then its PR must be greater than 0, but less than 1. You are talking about toolbar PR which is different to Google's internal PR that is used in the rankings. A PR<1 link will help your PR (by a small amount) and help your rankings with anchor text relevancy.
If the PR0 site do have same niches with your website, then yes, it might help. As mentioned before, PR0 do have some juice as well, just the PR juice still not enough for the webiste to reach PR1.
Yes what he said , thousands of new sites come onto the internet ever day, in between PR updates they may look linkless ( no green ) but check backlinks that may indicate true position.