Hi @Bruna-Ayako0,
good suggestion to Airbnb that the should provide a listing in which coutries passport copies are required by local registration law.
Regarding the tourist tax, Airbnb did already a first approach and for some first cities in the France they collect it from the guests and then pay to the appropriate communities. However there are many communities especially in european where the guest needs to pay the tourist tax (small amounts between a few cents up to 3 Euros per day per person, depending on age, season and several other facts) to the community and the host is obliged to collect it as a withholding amount and then transfer the money to the finance dept. of his community. It will be a long way until Airbnb can take care of all these various local regulations...!
But regarding your stay in Italy I agree that the host should have mentioned this in the listing. If you look to my listing it is clearly outlined, that the tourist tax has to be paid additionally after check-in (because there is no extra price field yet in the Airbnb tool for Germany).
If you are unsure about any demands from your host, you also can google about Tourist Tax in those countries/communities and I am sure you will get some results, of course most of them will be in the home language of this country but any on-line translator can give you a feeling what the local is about. Also if hosts in specific countries are requiring additional information like passport numbers and home addresses, this tells you that your host is following the local regulations as well and you stay in a legal lodging.