Moscow has districts, residential areas very quiet and which remind me of the city of 110,000 where I live when in Russia.. THAT city of 110K reminds me of the town of 5000 I live in in Texas. Moscow is very safe. No nuts with gunz and no gun nutz. People basically mind their own business. Many will be seen out after dark, WELL after dark as December sees the sun set at 4:pm.
Work as a teacher will net you enough to live on if you have a flat. OUTSIDE Moscow, a flat (at least are advertised) will cost $30K or so, CDN. 1.5 million rubles. Probably these are at the end of the metro line. To rent a flat, you would probably live below the standards you would want.
If you marry THEN getting permission to live in Russia is easier, MUCH easier. I warn you though, once you get used to Russia it is hard to leave. Every year it is harder for me to leave. I happen to love the small town, country life I have in USA, though. But Russia has a lot of reason to love life there.