The jobs you list would definitely not fall under the common definition of unskilled labor. Most of them are trades.
PonyOfWar
Aside from London (where I didn't really talk to anyone but my sister who lives there), I spent 2 weeks traveling solo by train around England, staying in Bath, Shrewsbury, York and Scarborough and visiting some of the surrounding towns and villages. I'm sure it helped that it's a country where I have a good grasp of the local language unlike, say, Italy, where I could barely make myself understood. But I had lots of random friendly conversations with strangers in the UK and no negative experiences at all. Way more friendly than the average German for sure.
Big-city people are generally less friendly, so I do believe you that it's a different matter for London. It's the same for e.g. Tokyo, where people are way more cold than in the rest of Japan. And I guess you get a different perspective as a local than as a visitor. Several people in this thread have mentioned Germany, which does surprise me as a German.
It will have an effect on other countries, but fuck up the US economy the worst. Other countries have the benefit of having 190+ other countries to do trade with. Over the next few years, they will increasingly go for alternatives to whatever they've previously traded with the US. Thanks to the stable genius, the US will permanently be left poorer, while other countries will soon have economic growth again.
Yeah the democrats have been a disappointment. I'd kinda see that as a reason to protest all the harder though. Using more disruptive measures like general strikes as well. Make them listen. Protest movements have overthrown tyrannical regimes before. Gets harder the more they've consolidated their power though.
There were many events over the last few years that brought us closer to a potential WW3, but I don't think the market crash will play a major role in that regard, no.