1) Is the floor of the toilet considered najis, If there is najis and it is removed, will the water in the floor of the toilet still be considered najasat?

2) One of my local teacher says if the toilet is being shared with people who don’t observe the taharat and najasat, the floor is najis.
Is it correct? Then if it is correct how do I deal with situation when I everytime go to toilet, I just feel stressed about my dress being najis or my body being najis since water will splash on it?

by

1) If the najasat is fully removed then the water will not be considered najis, however it is better to take precautions

2) Better to take precaution as much as possible in that case. If dress or body becomes najis then clean it before praying