Δεν είναι ωραίο να δουλεύετε χωρίς σύστημα...
Why "we work with no system" is not accepted?
we work with no system doesn't sound right in English. You can say - We do not work with a system or as the software mentions - We work without a system
Sounds fine to me
Same here. It's a completely acceptable way to negate a noun.
Is the "σύστημα" like a computer system, or a set of methods used to accomplish a task?
The latter, unless defined otherwise.
Does unsystematcally work?