Tahaarat

Will touching a dry impurity make one impure?

Q: I am currently abroad and I have been doubting everything recently. I was recently told that theres a potential of lard (pig fat) being used in the making of bread here in some of the bakeries. My friends eat that bread because they are non Muslims.

My question is, if they were to eat the bread which is a dry entity and then touch me with it after they are done, would I become najis, or does impurity only travel through wetness? 

Making wudhu in a place where impurity was washed

Q: I had an infection on my toe which I washed off (whatever was coming out of the infection) in the tub. A little later, while the tub was still wet, I was making wudu in the tub and some water splashed back to me when I washed my face. Was this water impure? Also, when I am filling up a jug to use to make istinja, I sometimes place my finger in the water to check how warm it is. Does this affect the ability of the water to purify?