I didn't find aly saying rakhi chhotu insulting in any way... Everyday everyone does these light jokes in real life too... Har cheez dill pr lene lage to zindagi mushkil hojaegi darling. Rakhi does the same aate jaate love lapaata and what not! Agar rakhi ki baaten fun m lete ho to ye b lelo... 
Kitchen Scene
Rakhi: to main idhar he krdun ta**ii kitchen m? Saaf krdegi? 
Jasmine : wese b 3n dafa flush kiya hai ye bhi krdungi.
I'm sorry no one is obligated to tolerate someone's personal shit and it's not like they've been mocking her about it. In start they did announce that please keep the washroom clean without taking anyone's name rahul mahajan has to even deal with the sanitary pads also.. Apparently rakhi didn't listen. When I've to use public washrooms I go and first see if it is clean then only I use it... And make sure that I don't make a mess there so someone that comes after me is not uncomfortable using it.. So obviously it is common washroom and she is told a billion times now on TV and God knows how many times off TV but if she isn't still listening no one is supposed to put up with her shit. 
Arshi seems hygienic and I've not seen anyone talking about her hygiene except rakhi who said iske banaae khaane m s baal nikalte hen... 
If someone smells bad again no one is obligated to suffer because of your unhygienic lifestyle. 
Also if you don't want to change your lifestyle then refrain from going into someone's personal space e.g rakhi kissing jasmine 3 to 4 times. 
About vikaas "munh s badboo arhi hai" it was in a fit of rage and they all talk shit when they fight with each other.... Vikas also have called arshi ghatiya aurat gandagi etc etc...
 So just because "eliteclass" think they are superior to someone doesn't mean they are wrong everytime.