Reverse and parallele animation

I didn't find anything on the subject. I have two issues :

- Being able to play several animations on a single object at the same time. I tried adding an override track but it didn't do the trick. The first animation get stuck.

- Being able to set a negative animation speed to play it reverse. I guess it wouldn't be hard to do but it seems like its not supported.

I believe I saw somewhere it was not available yet. Am I wrong and didn't see the option ?