What is the best way to survive in Detroit?

It's not a case of "survive". Detroit is just a city, and you can take unwise risks there or in the outback of Australia just as easily. Travelling isn't some rare art, it's a life skill that you need to learn. When you plan to go somewhere, find the relevant information - goodness me there's so much online - and plan accordingly.

Downtown is pretty safe in Detroit. Corktown is best avoided. Like any other place in the western world, if you roll out of a nightclub at 2 a.m. drunk and alone, you are vulnerable and at risk. If you stay with others, behave responsibly and return to a registered hotel or hostel, you will be fine.