Is it permissible, Islamically, to avoid someone who appears outwardly religious but does things that violate Islamic teachings, such as smoking, delaying prayers, and viewing immoral websites, knowing that this avoidance is limited to matters unrelated to work?

What was mentioned about your companion regarding negative characteristics (such as outward religiosity, smoking, delaying prayers, and chatting with girls online) necessitates declaring him a fasiq (transgressor). Following him in prayer does not invalidate the prayer according to the majority of scholars, but it is better to follow someone else. As for your avoiding speaking to him except within the bounds of work, if that will reform him, then do so. But if it is not beneficial or will increase his deviation from what is right, then do not do it.