The myth that China doesn't have violent crime isn't true. There just isn't much. I found people would sometimes warn me of a thief. Most apartments have all the windows barred. I don't worry about thieves at home, I don't lock my house. When I lived in the city I often left my keyes in my motorcycle.

 I've never felt safe crossing a road in China, cars will actually try to run over you. At home cars will stop except on major highways, cars will let cars out etc.

Then there's food, water, air safety.

 Home rules.

To me, it's about the same as back home : I never feel in danger, no serious threats. People are scared of gypsies, in Suzhou, people are scared of Uighur people...

The main crime in my home town are burglaries, and rebel teenagers without a cause. The main killers might be drunk driving and the Atlantic. Tourists are not used to the beach there, which feature serious waves, treacherous & deceptive currents, instable sand dunes, and a unique phenomenon called "baine" (an innocent pool of water on the beach filled in 20 seconds by up tides). Locals know the danger, tourists drown by batches since 50 years. No amount of information panels seems to do anything.

In Suzhou, my main safety issue is the driving. No lights on e-bikes even if it's all dark, people drive counter-way on the bike lane, cars might drive in the bike lane, extremely selfish driving, etc.

China's a mixed bag, but I'm not worried about my personal safety.

I have been to 29 countries and from a personal safety point, China is one of my favorites.  Yes, you have to be alert all the time because of cultural differences, but chances are much less to be mugged or murdered than in some countries, including my home country.  After all, I am 6'2' and considered to be a giant in China.

I find this question very hard to reply. In my opinion it depends very much how you define the safety.
What concerns of violant criminality so China is of course safer than majority of other countries in the world and therefore from my perspective very safe!
When we talk about pickpocketing and the danger to get cheated so I think majority of the places in China (and basically all so called developed cities in the Eastern coast) would rank very high in the most dangerous places list... As such it's not really safe from this point of view.
If you drive here so you may add another huge risk - it's not as bad as India or Pakistan but it's quite dangerous in comparison to basically any European country. From this perspective very unsafe.
And as part of this I may add my biggest fear in China - 'silent killers'!
The electric motorbikes so popular in all flat places in China (be it Shanghai or Chengdu!) - they silently come out of nowhere, always ready to hit you if you do not react fast ...
But overall I think China is quite OK and not very dangerous with proper precautions (may be with exception of traffic ).

I think I would be more likely to be attacked in the UK
Suffer racial abuse in China
Be a victim of theft in China
Be killed in a traffic accident in China
Die of disease in China
I would say China is probably a much more dangerous place especially as the police would respond in a much faster and efficient manner in the UK. If I was in an ambulance I would get to a hospital faster too.

The uk is more dangerous. Junkies and antisocial young men make the streets way more dangerous than china. They don't have the drinking culture that causes the main city streets to be so scary for foreigners and families at night. 

In saying that the 19 th century like safety awareness in china is terrifying at times. Ever got a taxi to the airport. My god. 100 kph with no seatbelt and a taxi weaving in and out of traffic. 

I would say Shanghai feels much safer than my hometown. Not sure about the rest of China though, and I'm sure there's parts of Shanghai I wouldn't go at night either.

WAY less safe, back home cars usually don't lock the doors automatically, people leave their house unlocked, shops don't have everything electronically tagged etc. 
I've witnessed more violence in real life on the streets in 4 years in China than I ever did back home.... and back home I went to the nasty neighborhoods for my after work beers. 

Then there is the risk of the building you are in collapsing, the electrical installations killing you, the gas exploding etc. All are nonexistent back home. 

Food... sigh, traffic. Well, funny story. Today I was driving along a small road. In the oposite direction came a lorry. I couldn't really move anywhere, car behind and all. So I just stop. The lorry-driver had pulled into my lane to to pass a parked vehicle (this is one of those situations where the rules says he should wait until oncoming traffic has passed) Anyway, after the lorry is safely parked in a bush, I continue to go where I was going. The driver committed lorrycide. What a toolbag. 

I feel safe here. I do not have any worries.

It's your employer you've got to worry about burglarizing you here.

It's your employer you've got to worry about burglarizing you here.

It varies by city. I live in Zhengzhou, for my sins, which is pretty safe at any time of day in terms of violence. As others have said it's the traffic which is the real risk to your life in China. But I've also visited Shanghai and Guangzhou and there are some dodgy types out at night, particularly in the tourist areas.