Hemorrhoids getting bigger and bigger as weeks progress! Should I just sit on a pillow till term?

Wont help a lot. Hemorrhoids during pregnancy are usually due to partial obstruction of the venous outflow. You may have better luck changing positions frequently to adjust the position of the uterus so that it doesn't impede blood flow. Laying on your back with a pillow under one hip or the other is something that might work for you.
Depends. Do not sit on an inflatable "donut" or prolonged sitting on the tpoilet seat as these will make it worse. A broad surfaced bed pillow may help, warm baths in plain water for 10-15 minutes if not contraindicated by your OB helps and bed rest with feet above hips will also help. Be sure your drinking adequate noncaffeinated fluids(80-100 oz per day) and deilivering will ultimately help the most.