naaaaaaaaaaa, common shower rooms are not un Islamic .Taking a group shower by males or females or by un married couples in bday suit is un Islamic. If a male female couple is married then it is not un Islamic either , for reference look Sahih Bukhari.
As for tatoos
ulema say that it is not permissible because it implies changing the creation of Allaah, as Allaah tells us that the Shaytaan said:
“ ‘and indeed I will order them to change the nature created by Allaah’” [al-Nisa’ 4:119 – interpretation of the meaning]
how does circumsicion, hair cuts etc come into play here
or diff types of plastic surgeries, ranging from augementations and transplants to cleft palette?