More than a third of our workers fall into this category. Less and less today. Some of our fields have houses close together for various reasons but there are few 'compounds' around. They have obvious advantages and disadvantages, but most missionaries prefer to be where the people are and so rent houses appropriately. I've heard of missionaries getting 'hired help'.
Many missionaries do.
It is not a case of extravagance but necessity. The simplest tasks can take much longer in a host culture and there is often high unemployment, especially among women. The cost of such help is much cheaper than one would expect to pay in their home country. It can benefit everybody concerned if paid help is obtained. You do, eventually, if you're a WECer.