i like that project and it would be cool if it succeeds. but how will they prevent people from selling alot of illegal stuff? that would hurt it open bazaars reputation.

This should make you more comfortable :
http://fortune.com/2015/06/25/openbazaar-not-silk-road/I personally don't think people will sell those Illegal stuff , even if there is they won't be a lot to do that because difference between Silk road & OpenBazaar is that Silk road was focusing on selling those stuff .