Our land (NE TX, variable rainfall, zone 7/

has historically been used for cattle grazing. We have a huge crop of wooly croton (better known locally as "stinkweed"). I'd say by biomass it outgrows the grass, and it has little use aside from seeds that are edible by ground birds (none appear to be in the area going by sightings, game camera pictures, etc).
Link:
http://essmextension.tamu.edu/plants/plant/annual-croton-woolly-croton/
"When these plants are abundant, they are generally associated with soil disturbance, lack of soil cover or overgrazing."
Our soil is very sandy (on top of a red clay base), and mostly compacted by the cows... so this fits. The local ag extension agent doesn't seem to know what kind of soil conditions it likes, what would outcompete it, or how to deal with it without involving herbicide.
The people we bought the land from only got it 4 years ago (they sold ~1/3 of their property), and say that they were told the soil needed to be limed. Lime increases the PH, which indicates that the soil is probably very acid (soil tests pending). I've researched liming, and it looks like distributing lime involves tilling the entire area that's being limed. That's a lot of work and a lot of soil disturbance.
We distributed a lot of clover seed last fall, and basically none of it took. We also tried planting some radish, okra, turnips, etc., and none of them took. The only edibles we've seen are a wild persimmon tree and some blackberry brambles.
Questions:
1) What plants can be used to increase the pH of the soil and improve its quality?
2) What useful pioneer plants are likely to do well in the same conditions that stinkweed does?
3) Should we "give up" and just lime the soil?
4) Should we wait on swales until after the soil has been improved some? My concern is that we might put swales in and then have to till through them to distribute lime if we can't find a natural solution.
thanks