Parker is the slum of Mars. If you just want to try to work the land for a living, this is where you'll be sent, although you'll still have to sell the ore at the corporation owned mills. It's just another way the EDF is keeping people down.
All in all, Parker is like a training grounds, most of the sector is urbanized. Having small settlements, like the Red Rock trading post, throughout the area. The Red Faction only has one safehouse, but has another abandoned one located not to far up the road. Parker sector was, obviously, named after the famous Red Faction soldier, who liberated mars from the nefarious Ultor Corporation. The funny thing is, Parker may still be alive, although not in this sector, but The Badlands.
There is only one high importance target in this sector, the ore refinary
The only real threat in this sector is the EDF, and even then it isn't that heavy. When a red alert is raised, don't expect tanks or gunships to make their way to your position. It is very rare to even see an APC make its way to you, often instead the staff car is used as troop transport.
After Alec destroys the old safehouse, the Voice of Mars will begin broadcasting that EDF forces have destroyed it, but a few guerrillas were still there and caused some casualties.