How can i set animation speed in Kickoff?

This is not possible at this time, even in Trunk.

Its quite slow at the moment, i mean that animation when you click that KDE logo and Kickoff opens

It is unlikely that the Plasma team will add settings to control the speed of that, or any other animations.

I note that after opening and closing it a few times it becomes much faster.

Can i remove that animation?

I think the animations is done to hide some graphical glitches when opening, I prefer it this way to how it was before, see https://bugs.kde.org/show_bug.cgi?id=218773