In our world, unskilled workers aren't totally unskilled, they'd count as scholars for the sake of being literate. Unskilled workers are people whose set of skills are so common they don't count as rare, so I think it's an argument to support the idea that farm laborers are mostly unskilled workers. The inequality is baked in the system, to the point that many peasants should be better off as slaves rather than free, impoverished men. Which is, historically, the exact reason slavery disappeared in the East Roman Empire: the richest landowners realized they were economically better off with serfs for unskilled labor. So I don't think it's unrealistic to have the 2sp a day be the wage that most people will ever get. 90% of the rural population and probably 60% of the urban population was "unskilled".
I'd however, take exception with the violence & crime part. Disease is a major part of life and epidemic killed many people so it's certainly intended, but I feel the violence & crime part apply mostly to adventurers. Much like their cost structure will be different, travelers will generally enjoy less protection. So they are ideal targets for violence, while locals are certainly not tougher, but could be avenged by their relatives, so they are riskier targets than some traveler sleeping in front of the door of a local temple. Also, law enforcement might care more about locals being robbed than a random stranger they won't ever see again reporting he was robbed in the woods.
Also, I kind of like the idea that peasants are just a bad winter aways from mass starvation (unless living in a world where magic is plentiful). They really needs adventurers to protect them. Would'nt you be more moved to help a village where the elders are coming to you saying "please protect us from the dragon, we have amassed all our riches and we can build you a shed, or give you two large hams and a wheel of cheese that we will miss this winter but don't worry we'll still have some bread some it's OK..." or "kill that dragon and I'll give you 14,543 gp taken off the emergency tax fund..."
Also, a 1:10 difference between unskilled and skilled labor doesn't strike me as extraordinary compared to the income inequalities present in Western Europe in the middle ages up to the age of Enlightenment (it went downhill with the 19th centry...). A mason or carpenter in England, mid 14th century, would earn roughly 8 times the wage of a porter, messenger or stable hand (but generally manservants would be fed and sheltered as you pointed out). And they were not the top of the qualified workers, it would go up with the specific trade and the risk taken.
The setting implied by the price list is indeed quite grim by our current standards.
Also, I wouldn't be keen on separating too much the economy for the NPCs and the economy for PCs. While most NPC activity can be abstracted away by virtue of the PC not looking, so they are in a quantum state, the price for wages is PC-facing. A PC can hire a hireling, unskilled, for 2 sp a day. That's the rule. So any normal player in my group will be tempted to do the experiment of hiring him for a whole year, in order to do the unskilled task of lugging their stuff. They will be able to look at the NPC all the time, having to survive on these 2 sp a day. "How can he eat? What? Does he provide for his family?". And suddenly the NPC spending (and whether he dies, can feed his child and so on) become totally observable by the players.