Old fault discovered after a new fault is created

Q: I purchased a brand-new stove last year from a Muslim brother who owns an appliance store. Two weeks ago, the thermostat blew. When the electrician opened the stove and was changing the thermostat, he noticed that the brand-new parts of the stove had been replaced with old, slightly damaged parts before it was sold to me. When I complained to the appliance store, they acknowledged the fault but were unhappy to give me a full refund because of the blown thermostat. What options do I have in Shari’ah?

Dancing

Q: I am a boy and I dance on instrumental music only. My form of dancing is waving and stunts and does not contain any vulgar and obscene dance moves. It is just simple movements of my hands and legs, and I am a solo dancer so there is no intermingling of sexes involved in it. If I earn money through dancing, will my earnings be considered haraam?

Wiping impurity off a flat surface

Q: My little brother got urine on his boots at school (at the bottom and top of shoe) and then walked from school to home in the snow, getting them wet. When he came home, he walked through the living room, spreading the wetness from his shoes all over the house. I did my best to wipe all the wetness off the floor but I don't even know all the places the water from his shoes got. Do I consider my living room to be impure? How can I make it pure again? I will have to mop the living room and the rest of the house, it that ok?