yes they are safe, I never read of any problem coming from such a site. As a webmaster of an adsense revenue sharing site, I know I have to make sure content posted on my site by members complies with adsense's TOS. For the well being of my members' adsense accounts as well as my own!
Adsense sharing sites are safe, DP used to share Adsense revenue (I don't know if they still do it) Just make sure to add the site url(s) to your list of allowed site if you are limiting the websites where your ads should appear https://www.google.com/adsense/publisher-whitelist-view
it still depends on the contents of such sites. if they are moderated by admins for good contents then they are safe
First of all, every revenue sharing sites, if approved by adsense, then they are very popular thats why they got approval. So, their is no harm but do not participate on those revenue sharing sites who have not got approval from adsense.
I have list of forums offer adsense sharing but I don't use it, because they ask PUB-ID... I don't think it is good idea to share PPUB-id...
VIBGYORtel, pub-id is a public information, what do you fear by "sharing it"? Try spyonweb.com you'll cry