You have fleet admiral, which gives attack bonus. Below are some more ideas. (Also if people think of better names, they should post it ) And I'm sure there are more ways to be creative and make IC more interesting.

Some of the more "normal" tags could be

"Cash Cow", who gets a boost in income bonus
"Secret Service", a boost in succeeding agent ops
"The Magician", a boost in succeeding magic ops

Some random ideas I have although I don't know how useful or how balanced it could be

"Bullet Train", *2 to speed% for the person's race bonus. Or just add 100% if you want some banker to move faster. (Numbers subject to balance changes)
"The Engineer", reduces build time on buildings and/or units by a certain X amount of ticks (where X is open to balance changes along with whether buildings and/or units are affected)
"The Crybaby", much easier to go into pmode (May be abused, but open to balance changes)
"The Ninja", cannot be opped (This may be too powerful, maybe cannot be PI-ed or Inilftrated or some other ops, open to balance changes)
"The FamilyBank", no resouce decay (keep in mind this person can still be opped)
"The Undead", does not lose any units in the battle if the planet is captured or blown up. (Basically if you win an attack, you don't lose the units)