If you link all posts together then it may create too many loops for the web crawler, so it may not index your site very well since it will only spend so much time traversing the links on your site. Like others have said, a selection of related post links should be good.
As regards the number of links on a page, the G webmaster guidelines used to suggest 100 as a reasonable limit. So maybe it would be ok to inter-link all 100 pages of a site on each page? But it would look a bit OTT with such a long list of links on thin-content pages I think.