Impurities on the ground

Q: Two days ago, there was dog sniffing the pathway for a long time. I saw a small handful puddle of wetness. So on that area I pushed the pram back and front again twice. After couple of days, my son used to play with the pram tyre by rolling it on his hand. He did that with wet hands and touched utensils with wet hands to eat and below where I have later placed utensils on top when wet. Now I know if a dog licked it we have to wash the earth 7 times. Now because of the saliva that has spread on my house must I wash each utensil that have been touched by him. 

Q: When my semen discharged from the place and some of it fell on my room mat but instantly I cleared the dirty place with a cloth. Now I'm confused, shoud I wash that particular place which got affected by my discharge or shoud I wash the whole mat?

Q: On my house carpet, sperm and urine has been on the carpet, however it has dried up and there's no trace left. Does the impurity from this area of the carpet transfer to people who step on the carpet? If not, what if someone with wet feet steps on the area. Also, does impurity transfer when it is wet or damp?

Q: Will a floor become pure (taahir) by mopping it three times for urine? As we stepped on the urine and walked while wet?

It will be done by mopping one time then dip the mop in new water then mop again and repeat two more times?

Q: I saw urine on the floor so I was wiping it but did not finish it when someone stepped on it but at that time color of water was not like urine but I was not finished. After I finished the same person again stepped on the clean wet floor. Will the floor again become impure or not?

Q: My child urinted outside when toilet training. How do I make the floor paak (taking into consideration it is a flatish, sandy land and not near a drain)? I poured water and left it to dry, do I need to repeat twice?

Q: I ride scooters and bikes to school. I rolled over non-halal foods/sandwich packages with leftover foods several times when riding on the streets. I live in the U.S. and the sandwiches are subway wraps with wet food oil and sauce and certainly not halal. Hence, the bike tire becomes impure. When I ride it in rainy days, the water splashes from the tire onto my shoes and pants. Since the bike tire is impure the water splash is impure. I have to go back home and wash them every time I pray and it severely impacts my life. However, I heard that walking or rubbing impurity against the ground makes the impure shoe pure. Does this ruling apply to a bike/scooter tires? If so then the bike tire can be regarded as pure as it rubs against the ground so many times?

Q: If urine on the floor is wiped with a wet cloth two times, but the traces of water and some dust is still there, will the floor be considered paak after drying?

Q: My question is regarding concrete floor and impurity. I know for a fact that some dry impurity fell on the concrete, so I wiped it once with a dry piece of tissue (and should have left it there). But for some reason I had poured water on it and it went underneath the basin of the bathroom. If I tried my best to soak up the water with tissue, would it be considered clean. Keeping in mind I poured water on it once. I was in a hurry because others needed to use the w/c.

Q: My maid mopped over my baby urine by mistake and she continued to mop with the same water in other rooms too. Now what should I do? Shall I mop 2 times again?