Do i have to max out every skill to be able to add next job skills?

I'm missing 5 SP on my Bishop.

And one warning: the SP assignment checks that you have at least 61 (or 67) in 1st job, 121 in 2nd, 151 in 3rd.
It *should* be checking that you have 61 (or 67) in 1st, 182 (or 188) in 1st+2nd, 333 (or 339) in 1st+2nd+3rd.

If for some reason you decide maxing out the last 2nd job skill is more important than some 3rd job skill - you can't. Any extra points in an earlier job come out of your 4th job SP.

I'm not sure whether you can still do it when levelling up normally.

If this is true, it actually rapes Arans because anyone who wasn't stupid spent 10~11 skill points from 3rd job maxing Final Charge and getting more Booster instead of getting 11 Whirlwind, which still misses as much as it doesn't stun by the way.