That is a pretty interesting topic but the answer to your question is too simple. As generally, not in games only, some stuff are retarded, stupid, but most of all legal although they're retarded and stupid themselves, the important word is legal. Ramming and blocking in IV mode is allowed, in fact going backwards in most of the IV races is allowed too because there is no rule to prevent that.
Even if you're going for a top and someone blocks/rams you or even drives backwards, you'll have to deal with it because it's not a valid reason to report someone. Plus the punishment wouldn't be too serious as there is no rule regarding that. On the other hand, some admins do punish for it because they find it stupid and irritating, but that is quite more individual based and how the admin understands your situation. Final conclusion, simply avoid being blocked and rammed, ram people, block them yourself as much as you wish and try to top meanwhile if you have the chance for it. Not sure if this deserves a topic though but I assume you're frustrated about it so you'll have to accept it.