Is it allowed to put adsense ads on a page where there are links of different sites only, but no content? I have found such a site: http://www.top20free.com which is a autorank type site which lists its partner sites according to incoming hits.
I think yes it is possible since links can be seen as content.
Yes I think so too.
It is allowed on news sites which only fetch RSS Feeds so why not on such a website?
As long as the content is interesting to users it should be ok for Adsense too.