I'd add "Check out the neighbors". Doing a drive by visual check can give a lot of information about one's potential neighbors. But talking with them is far more revealing.
Also I'd add "Check with the authorities and your local government rep (councilperson, mayor office, etc) about future changes planned for the area." Having your road widened into a major highway may not fit with your vision. Or having the new school complex built across the street may crimp your style.
It's never too late to start! I retired to homestead on the slopes of Mauna Loa, an active volcano. I relate snippets of my endeavor on my blog : www.kaufarmer.blogspot.com
For those with school aged children, another important factor is schooling, and transportation.
If the school district provides busing, at what hour of the morning does the child need to be at the pick up spot?
5:00 a.m. standing on a country road in a chilly December blizzard is not a good way for any kid to start the day.
I know people who needed to ride a bus for 2 hours morning and afternoon. That's 4 hours added to their class time!
Also, if they want to participate in sports, glee club or any other after school activities, that means that their bus will not bring them home.
How far will you need to drive to pick them up on those days? In what kind of weather?
Dale mentioned zoning, but it deserves to be emphasized. If you are planning to homestead, it will probably mean growing both plants and animals. You will want to know whether or not the property is zoned so that you are legally able to do that. If you are planning on a commercial operation, you will want to know what your zoning allows in terms of a farmstand, or other retail outlet on your property, not to mention possible restrictions on the numbers of any livestock you may maintain on the property.
You might want to pay attention to municipal and state regulations about how many animals you can raise/sell, where thresholds fall in terms of being covered (or not) by the regulations.
Especially in the Western US you might want to pay attention to the laws on water rights - will catching roof water get you fined? Can building a swale be a legal violation?
Many of these laws are far from intuitive and can place crippling restrictions on your homesteading/farming plans.
Everything Peter said. And, check out the zoning of all nearby property. Several people have built homes within half a mile of my place since I bought it 12 years ago. None have called me, to inquire about my future plans. I'm zoned "resource management". I could start a sawmill, a log sorting or rock crushing operation. I don't have the money or the desire, but they should have inquired. Change of use on nearby land can affect value and enjoyment of your land.