Yes, sudo is a choice, but it raises up other security questions.
It looks like yaourt has enough to build dependency graph for selected packages and exclude rejected/build-failed with dependent ones using BFS. Or you meant something else? (Sorry, i didn't looked at sources, yet)

Hi, Sorry, i would write in English cause don't know French. BTW in "British English" interface at registration control question is still in French :] Today I was updating my system using yaourt and found few unconvinient things updating AUR packages. 1. Answering negative to the question ...