HI Franck,
I"ll have to check on that first question. I know there was a feature request related to moving keys with frames but I can't recall if the feature was implemented. The answer to your question will likely depend on whether that feature has been implemented/changed.
With regard to the second, changing the order of drawings in a Level... one way would be to Right Click and select Reverse. We can select two, three... however many we want and use that.
We should always start a sequence with a 1 and not a zero... that may related to the crash you are experiencing. I've ran afoul of that issue before.