answers to your questions
posted by Ben Simpson in Shenzhen forum
is it difficult to cross the boarder weekly for a foreigner? No
what language should I learn? whatever your workplace needs. HK speaks Cantonese, but the rest of China is all learning Mandarin. It's a hard choice. Many people in HK can understand Mandarin, but they don't speak it to each other. I picked Mandarin.
are there any major drawbacks to living in Shenzhen vs. HK? look into your tax liability.
are there any things I have not thought of that will pose an issue? depending on what type of visa you have, you might not be allowed to live in Shenzhen. A HK work visa is not good for Shenzhen.