When we speak about traveling to Russia, we should bear in mind how big it is and how different each region might be. Any way you’d better avoid jokes about Siberian bears who play balalaika while drinking vodka. It is very rare now when you can meet such an example in Russia. Therefore by making laugh about that you may offend Russians who feel sorry about those endangered species. Second, it might be not a good idea to joke about Russia and all Russian staff being in Russia. Russians have very pore sense of humour and do not understand if you are sarcastic and ironic or you literally mean what you say. So, be cleverer, simplify what you say in short and very clear sentences, - that how you can avoid a conflict in Russia. Finally, Russians are the best readers of body language and emotions! So, it might have sense not to show your face to a Russian and to keep a distance in order to disable him judge your intentions even if you have nothing to say. Very finally, please remember that Russians believe that they are very funny and do hospital people! Enjoy your stay in mother Russia :)