Good pasture, if properly maintained can be some of the most
sustainable land use available. Do yourself a favor, and watch Greg Judy's optimistic video on pasture management:
http://www.youtube.com/watch?v=W6HGKSvjk5Q Good pasture will heal the land, and build new soil if done properly. Scattered legume
trees (like
Black Locust) as a pioneer species will begin to
feed the soil, provide shade for livestock in the heat of summer, as well as an endless supply of fuel
wood.
The "tillable" land can provide income to maintain your family while you continue to develop the remaining acreage. In an 'ideal' world, you would not need income, but we live in the real world, where tax assessors and
mortgage lenders still exist, and the utility companies, and others keep asking for money. Your 30 tillable acres
should be sufficient to satisfy the needs of the real world, and help finance your goals.
Looking at the video, I see no reason why you couldn't do it. Keeping a 100 year farm in the family for your children/grand children should be a high priority. Otherwise, the costs of land and food may be out of their reach in a few decades.
Go for it! If you don't, a few years down the line, you will probably be kicking yourself in the ass!