Rand seems to think he'll quit and head home.
That might all change with new happy Rand. The impression and feel I got of him in tGS was of a guy desperately trying to reach the finish line before his go cart falls to pieces, or like when you walk balancing on the rail of the train tracks, and as you come to the end of the bridge and your balance is starting to go, you start walking faster and less carefully, just trying to reach whatever marker you are aiming for before you lose your balance altogether and have to step down. Likewise, Rand seemed to just be trying hold things together in a slap dash fashion to get to the Last Battle so he can be done. Hopefully his new outlook will have him trying to do the job properly and get things working right, even if some things likE Arad Domon are beyond salvaging.



I would say yes to most of your questions, although the tGS prologue (Graendal's PoV) shows that there are settlements and agriculture of a sort in the Blight. Beyond that, Trollocs seem willing to chow down on anything, as well as being mere constructs and constructs tainted with the Shadow at that, so it is entirely possible they can sustain themselves on what can be hunted or gathered in the Blight. As you say, they also probably eat one another. Given that they are not a natural race, and are man-made with the Dark One's malignant touch involved in that process, they probably produce a lot of freaks and throwbacks and monstrosities. I would think that whole, healthy and normal births would be the exceptions and the useless freaks and sports would be much more likely to occur. Even if they do produce a significant proportion of normal Trollocs, Trolloc society is probably of the grimmest & most Hobbesian sort, producing many corpses on a daily basis.
Another issue with sustaining the Trolloc population might be that they have a short and fast lifecycle. Think about the history of the Trollocs in the AoL - they were designed, made and raised in large numbers to form armies, which, according to the BWB, turned out to be nearly useless since they were almost impossible to control, before their offspring provided the means of that control - the Myrdraal. This was a complete surprise to the Forsaken, who had no hand in the design or making of the Myrdraal. But the Myrdraal were born and grew to maturity and enough of them demonstrated useful traits fast enough that they were not destroyed out of hand as soon as they appeared, and the Trollocs were still around for the Myrdraal to control. For this sequence of events to occur, their must be a VERY rapid growth issue somewhere. How would the human-sized & human-appearing baby Myrdraal not get tossed in the dumpster by the Trollocs' overseers and breeding experts right off the bat? When you want huge and monstrous human-animal hybrid brutes, and you get a pale creepy baby that looks totally human except for lacking eyes, you'd have to be a little disappointed, no? And why would they keep these useless and uncontrollable monsters around for a couple decades before the first Myrdraal managed to grow to maturity and reveal its ability to control Trollocs?
If the Trolloc/Myrdraal lifecycle is only a couple of years to grow into maturity, obviously they do not need to sustain as much food. They can keep the population relatively small until it is time for one of those millenial irruptions and then step up the breeding program to suddenly explode their population into massive numbers and promptly turn them loose on the lands south of the Blight, without having to feed them or sustain them for long. And if they grow really fast, you can afford to chop up more than half of your army to feed the other half, because new ones are coming almost as fast as you can butcher them. If their rapid maturity is matched by a proportionally shorter lifespan, then you also have lots of dead old Trollocs lying around to eat.

There are a lot of possibilities, is my main point, and the idea of Trollocs living mainly on Trolloc meat is not as ridiculous as it might seem, when you are used to human lives & society. Don't forget that even in the most advanced pre-industrial human societies, lots of, if not most, kids died before they were two. I sincerely doubt that Trolloc medicine and hygene are superior to that of medieval Europe or the ancient Romans and Greeks.