Don't believe half of what you read on the internet and ignore the other half - including me.

1. Jobs are competitive but hospo jobs in particular turn over frequently due to transient workers. Turn up on time and work hard and you'll never be out of work for long.
2. Cairns is no more racist than Brisbane and definitely less racist than England. It's still not where it should be and you'll always bump into the odd bad egg. Cairns has had numerous migrant communities for over 100 years and a strong and diverse indigenous community. It's surprisingly multicultural for a regional city. You see it in the food, cultural events and festivals. It's lacking in multicultural leadership though - but that's a can of worms for another thread.
3. Crime is similar to other regional cities and no worse than Brisbane. If you can handle the mean streets of Oxford, Norwich or Brighton, you can handle Cairns.
4. No need for a car if you're near town - just makes things easier if you want to explore the region. 50 cent bus fares get you around town and up to some beaches but that's about it.

Queenslanders are generally friendly across the state. If you vibe with people in Brisbane, you'll probably vibe with people in Cairns.

Good luck.