Ours will sit nicely (I don't feed them while we cuddle them, they have breakfast and supper so they know they get fed and when).
They'll cuddle up , usually making for the left shoulder.
They'll curl up into a croissant shape or tuck their feet in like cats do. That's not the action of an animal that is poised to flee.
A couple of ours have fallen asleep though most of the time our trio are too busy chattering to each other to sleep.
We sit on the floor with them, they'll scoot round and climb off and on DD and I.
I agree they never 100% trust their Food Provider (that's their kinder name for us 
).
But most domesticated animals have a symbiotic relationship with their humans.
We give them security,food,,safety,routine and a correct environment (company,health care, freedom to express themselves in their group)
So though they don't live a natural existence like a wild animal, they have good trade off I reckon.
And though there are 10000s out there, we've made a difference to our pigs' lives , I think.
GP5 was uncuddly when we got her, she's settled down really well. I often think she's wishing she was Somewhere Else but she'll tolerate me for a while.
You need to read all the piggie threads Shoes , you'll be ordering hutches and runs before you finish