Thanks!IMO, Google looks at each page while counting affiliate links - not the entire site.
For a 4000 word post, I wouldn't have more than 10 affiliate links. For 1000 to 2000 word articles, I try to limit the number of affiliate links to 7.
Also, you would not want to have affiliate links above the fold.
Some sites have way more than 10 affiliate links - and Google doesn't seem to care about that right now. But you never know when things might change.
I wouldn't nofollow every outbound link - only affiliate links. If you nofollow every outbound link, you are in essence telling Google you do not trust any of the sites you link to - and that isn't a good signal to give Google.
Follow up question, by above the fold you mean above the h1 or h2 tabs right? The way I am setting up my site is an essential item list and they items flow naturally into the content. However I have like 50 Amazon items, do you suggest breaking them up into multiple posts like a Part 1, 2 and 3?