I think working on illustration specifically would be most likely to make you better in the other fields as well.
But then I might be a bit biased in that direction. ^.^

I think your approach to animation is great so far. But I believe you can go even farther. I mean look at animators like Don Blooth and Miyazaki. The animation from these two are just amazing and I bet you can be just as good as they are.

If I had to pick one of the first four I would say animation as it forces you to abosultyelty understand movement much more then the others while the others ones all have skills that overlap with animation skills I think while animation again has that extra in depth focus on undertsnading movement

illustration
animation
more mangas
concept art
other

hmmmmm I feel all of the first for are kind of inter related for you in that they all seem to related to your careers goals as far as I can tell and all have skill overlap that would benefit each other....hmmm I guess I shall vote other

hard to say O_o
u are preety good in animation and in concept artist line too O_o

look like u are also preety confuse XD

I think you should add more complexity in your drawings. (so illustration, but I felt the need to specify)

improving animation is alright and all, but its too time-consuming if you are solo'ing it, and I don't think it is that worth it.

Yop, so more better drawings