Anything is possible if you know how to write php code to do it. These features are not out of the box or included in any tutorials.
Cross selling depends on how you want to create and maintain those cross selling relationships? Do you want to do "users who viewed this item also viewed", or "users that purchased this item have also purchased", or do you want to maintain your own list of cross selling relationships that are maintained through an administrative back end. All are possible if you know what you are doing with general php and mySQL knowledge.
Affiliates are also possible. Again it involves database design and the creative application of WebAssist tools like DataAssist to pull off and may require some hand coding to smooth out the edges and make it work exactly how you would want.
WebAssist will likely tackle these issues and create tutorials or even extension improvements to facilitate this more easily in the future, but again there are no tuturials currently available.