I am in my thirties, and a virginia native who lived in Oxford for 3 years and LOVED it.
First - there is a small airport in Oxford. The nearest commercial airport is one hour north in Memphis. There is also an airport in Jackson - 2 hours south.
Second - you should be just fine on that income. In fact, you will be making more than most. The cost of housing is high in relation to the rest of Mississippi - not U.S., and if you decide to live about 5 - 10 minutes outside of town you can get a killer deal.
Third - dating.... yes there are single people in Oxford. I dated while I lived there but didn't find anyone to get serious about - see answer 5.
Fourth - I have no idea about duck hunting, but Mississippi is a very hunting-friendly part of the country. We had deer all the time which my friends would kill and prepare.
Fifth - the area in not conservative in my opinion. The laws tend to be conservative, but the people are not. Oxford has a thriving music and art scene, and the people tend to be creative types. Now, this is only MY experience. I gravitate toward people who are non traditional, so take it for what it's worth. I am sure that there are conservative types there too, but I tended to avoid them

Hope this helps.