Indeed, I only generally do a full reassignment every 10 years if needed as it takes that long to get a sizable number of new officers who may be better than the current ones. Once someone is in position they will generally stay there for considerable ammount of time.

Once you get the hang of the officers screen it isn't particularly time consuming or confusing. Make good use of the search fuctions on the right of the screen. One thing to note, you need to assign the commander of a task group HQ before you can assign the individual area officers for that HQ. Also teams only show up in the assignments list if they are not full.

My usual criteria for ranks

r1 - Entry rank, useless officers stay at this rank
r2 - Promoted to this if assigned to any position. Primarily commercial vessels and fighter/FAC commanders will remain at this level.
r3 - Promoted to this is member of a team, or commander of lead vessel of FAC/corvette taskgroup. All commanders of destroyer and heavier vessels are also at least this rank.
r4 - Promoted to this if head of a team, or commander of central vessel of a destroyer/cruiser taskgroup. All commanders of battleship and heavier vessels are also at least this rank.
r5 - Promoted to this if assigned as an officer of a taskforce HQ. Also commanders of central vessel of battleship/dreadnaught taskgroups.
r6 - Promoted to this if commander of taskforce HQ.
r7+ - Only used if I want to distinguish particular officers

For ground force officers it is simpler

r1 - unassigned officers
r2 - assigned to units
r3 - assigned to Brigade HQ's
r4 - assigned to Divisional HQ's

I'll promote/demote to match the rank of the task that the officer is assigned to. Usually I'll promote to the rank at the time of assigning an officer and every 10 years or so will do a overview and may unassign all officers of a type and reassign them to posts by their bonuses, promoting or demoting them as neccessary.

I always do it manually, but thats partly because I always leave the lowers rank of officers as the pool of 'don't have any use for you' officers, like the ground forces officers who have no skills whatsoever. that way if I see a officer has died/retired due to ill health in the events list, I don't need to care about it if they are the lowest rank.

Do you folks hand assign staff officers? or let the game do it for you?
I originally handled staff officer assignments manually, but recently I've been using (too) many Task Forces and it got tedious so I let the game handle staff officer assignments once I put the commander in place.... (it WILL auto-assign staff officers at that point, right? if not I am without a lot of potential bonuses )

On that vein, do you guys handle ship assignments manually? or use the auto-assign?
I have auto-assign turned on with a 2 year rotation, but I manually assign officers to my 'ships of the line'.

And lastly, do you folks use automatic promotions? or do you manually do them?
I have only ever had promotions turned on so I don't even know how to promote.

I am just trying to get an idea of any pros/cons of manual vs auto in those cases.
I think with my next big game -I'll probably do an AAR or community-involvement game with it- I'll try more manual control over things to add roleplaying/community flare.

I think he means the overall commander of the Fleet Staff.

What's the best traits for the Commander?

Yes. Not quite sure whether it simply adds to relevant officers skill to that of each ships commander for each ship in the taskforce or if it is a partial bonus.

And yes diplomacy for public affairs. You also want your operations officer to have crew traing in addition to operations if possible for training your task groups. The taskforce commander adds a portion of all of his bonuses to the relevent area.