Ok, for various reasons I'm committed to making a Tactical captain work on a Science vessel.
I have a Varanus, which is a KDF ship, but I figure folks Fed-side probably have more experience with this.
A Varanus is very much like a Deep Space Science Vessel (same boffs, same consoles, same speed/maneuvering), so that's really my main comparison.
Tactical initiative isn't leveraged well with only 2 tactical abilities (though it DOES help the team, so there's that).
Damage is low on the ship (no cannons, only 3 fore weapons, only 2 tac consoles), the captain lacks the debuff/control elements of a science captain. So you end up with a ship that doesn't do as much damage as a dps ship and is light on tricks.
Now I've done decently in STFs and Ker'rat with 3 DBB, 3 turrets. But I'd like to spruce it up, if possible, to the point where I'm not just 'getting by' in true pvp.
Tac Lt: Fire at Will, Beam Overload II
Engineer Lt: Emergency power to shields, Emergency power to weapons II
Engineer Ensign: Engineering team
Science Cmdr: Hazard emitters, Science team II, Energy Siphon II, Tyken's Rift III
Science Lt.C: Tractor beam, Polarize Hull II, Feedback Pulse II
I'm not sure Tyken's Rift III leverages this character very well, though it seems to work nicely. Energy siphon is mainly to provide me with plenty of power. If it harms enemies, then that's cool, too.