Imigrating from china

I have been talking with a girl from china for over a year now and we have meet I am planning to go back to china agian and meet her family. We have talked about getting married and discussed living in both countries. I know china dose not support dule citizenship though. From another post I read I understand its best to get married and then apply for a spouse visa.

1-What factors will determin if a spouse visa is issued ?
2-How long dose the process take ?
3-How long after can she move here and can she move while the visa is
being proccesed ?
4- Any advice to make it easyer ?

I had truble navigating to answers on some of the links