Loop ddj1000

Hello everyone!
I have 2 question about Loop functions on DDJ 1000
1) how can I select how many beats to loop (es 1/4 1/2 1 ecc) before starting the loop?
2)When I play 2 or more tracks and I loop one if I move the jog of the not lopped one to regolate it the looped track moves along with the other one slowing down or fastening, so that I cannot regulate one track at a time, the only way to do it it’s without sync.
Is there a way to do it?

I am try to do the same things I did with SX, which was better 😤