Hi mate,
1. Regarding status, it very much depends on the booking class you are typically going to fly in. As a rough guide: is it going to be
- very cheap Economy
- cheap Economy
- medium-prcied Economy
- expensive Economy
- cheap Business
- expensive Business
- First?
Depending on this, miles (and, consequently, status) will differ with different programs. If you are not flying cheap Economy, it should be possible for you to achieve Skyteam Elite +, albeit not necessarily with an Asian FFP.
2. Regarding upgrades: Unless you fly expensive Economy fares and do not care whether you use your miles wisely, you will find that within Skyteam upgrade rules are only reasonable if you would like to upgrade on the very airline that your FFP is from. So this should make you have a close look at China Southern, China Eastern, or Korean's FFP. (You might also wish to consider flying with CI (via TPE) as they are going to join Skyteam in September. Note, however, that currently you can earn status with them only by flying CI. But this might well change once they have joined Skyteam.)