uhh is this normal in kMS?

Yep, thats normal.

Highest level char gets BotS level equal to 10% of the 2nd highest character's level

All other characters gets BotS level equal to 10% of your highest character's level.

SO yeah, Cygnus is pretty much deemed useless unless you want to be OP at the beginning.

I made a NW on Keyaki and already hitting 1k on hits before 2nd job advance..

So if you have 2 level 200, always +20 attack?