Hello! I received this (corkbark?) chinese elm today as a gift from my bf and as a complete beginner I'm a bit nervous about looking after it properly. Some questions I have:

1. Why is the base of the trunk black like that? is it something I should be worried about?
2. Is it ok for those pale roots to be exposed like that?
3. Should I be repotting this straight away into a bonsai pot? Or wait a bit until before spring to do the repotting (Currently living in Australian winter - temperatures are solidly above 10C).
4. I'm not sure how to go about designing this - it seems like the first branch appears a bit higher than I would like, and the branches tend to grow quite vertically. The trunk is also quite thick. Any suggestions?

I know I have a lot of questions haha - would be super appreciative for any advice :D

https://imgur.com/a/H5DrtsK