I live in a small deep-red town, so I'll try to give my take on a few here.
2. Imagine you lived in a town where 99% of the population is not racist, but that 1% that is racist is blatantly so. They don't do thing subtly, but they openly use racial slurs and make it known that they don't like or trust people of a certain ethnicity.
Now imagine someone comes into town and when they happen to see someone of color they subtly walk to the other side of the road, or quickly double check to make sure their wallet is still there after they pass by.
To many (most?) people in the town, they likely wouldn't perceive this as being racist at all. Racism to them is walking into the passerby intentionally and saying something crude like, "Watch where you are going, *!"
When you spend your entire life thinking that this is what a racist is, Trump can seem incredibly tame by comparison.
Now we can get into a completely different discussion about whether those people truly are racist for not recognizing racism, not ostracizing the few blatantly racist people, etc, but in my experience nearly all of those people are making a genuine effort to be accepting of others and aren't intentionally racist. They have just grown up in a completely different environment/culture than what you would get growing up in a city, and their opinion of what is racism isn't the same as yours.
4. Where I grew up, something like 75% or more of the jobs were at factories. Toys, factory equipment, bicycles, fiberglass, metal, etc all came out of the town. And the people working these jobs weren't lazy - they would work 60+ hours every week, often working Saturdays, long overlapping shifts, and the factory would run 24/7. They even dealt with dangerous equipment (it isn't uncommon to see people missing fingers here) where they needed to pay attention to what they were doing all the time without any additional compensation. But they were happy. They could provide for their family. They could make enough to pay for a $100k house and their wife could stay at home and watch the kids because he likely was working and couldn't help out. Wages were never amazing, but they got by.
Now for whatever reason - automation, outsourcing, immigration, or whatever else - many of those jobs are gone, and now these people who previously would bust their asses to get by are still trying to bust their asses, but they are all fighting for the few jobs remaining. Wages are down (more workers than are needed by jobs). Spouses are working to try to help pay the bills. Despite all of that, things just don't look like they are getting better anytime soon. There simply aren't enough jobs available for them.
In cities service jobs can often help fill this gap, but in small towns it typically isn't enough. And many people don't want to, or can't afford to move. They are already barely able to pay their $400/mo mortgage and nobody would want to move to their prospect free town, so who are they going to sell their house to? They have grandparents in the area who need their help. They have kids 6 years into school with friends they don't want to uproot. So they do what they can, take what work they can, and get by hoping and praying that someone will take notice of their struggle and try to help them out. And the median income continues to decrease.