1. You can stay in China for 182 days ,1day=1day ( of course )
2. Do not know what will happen, since I came back in time. I suggest you not try that.
3. Typically you should stay half year in Canada
4. 5. 6. Do not know
7. If you give up this time, why will you apply again in the future?

My suggestion is a man should make sound decision according to your long term goal. Just choose the way you want to go.

Good luck.