Use other fast file-hosts to to upload short zipped attachment. Here are some good ones:
http://ge.tt
http://megafiles.se
http://mightyupload.com
http://billionuploads.com
https://anonfiles.com/
http://www.sendspace.com
http://www.1fichier.com/en

Not really.

Site function like submitting a comment also takes long time.

Not really. I think it's probably a server load issue(?) Site functions starts responding late like: any url on animetosho loads after waiting for long time. This happens after I browse through a lot of anime episodes here in a short time.

is there any other host who makes possible to import stuff in our own accounts, like mega?

This is a really great site, thanks you so much, I've been looking for anime DLL site since otakucop is down, and devhost is pretty much filling its lost right now :)

// The only thing is the "Episode Updates Page" is so hard to see (distinguish the shows I mean) hope you can do sth about it, thanks for the great site again :*

Don't sweat it, you're doing a great job! (And I'm writing this while having the shakes from anime withdrawal.)