I have heard many rules about whether or not girls who have reached puberty and wear hijaab can show their feet in front of men, is it haraam in Islam?
The feet must be covered
I work as a nurse that may require for me to take care of men at my work (giving male and female patients shower, changing their clothes etc). But I do not do this everyday but every once and a while I may be required to do them.
Yes, you can practice your job as a nurse. You can touch and see only what you need to see and touch to treat patients.
Yes it is permissible
Only shaving the head is Haram for women in Islam. Any other matters such as fixing the eyebrows is permissible but only for the Mahram to see.