Normal resting heart rate is between 75-85, when walking around it can jump to 90-100, all the way to 160 when excercising. normal?

Heart rate increase: Yes this is normal. Exercise places additional demands to get blood, etc to the muscles. So the heart rate increases to meet this demand.

Yes: Your target heart rate, in absence of heart disease, can go up to 160 during vigorous exercise, to calculate it , it should be 55-85% of your maximum heart rate (220 - your age) which would be around 160. Target Heart rate is the rate that your heart can handle to benefit from aerobic exercise, wish you wellness