Do Haven Advisors have a base Bonus to Havens?

[enricofermi2]

Do haven advisors have any effect if the haven has 0 rebels working on there specific job?

[Traul]

Soldiers do some recruiting on their own even with no rebels. AFAIK engineers and scientists do not.

[TheSuit]

Soldier can track down Faceless

[Sabaithal]

Engineers increase supply income. Scientists increase intel income.

Soldiers provide a bonus in recruitment, and can narrow down faceless, though you really do need to give them officer training for them to have a decent chance at doing this in a timely fashion (captain should be enough, anything higher isn't worth the effort for diminishing returns).