So - I've been playing this game for about 2 weeks now, happily flying around in escort not caring much for bridge officers. After a while I changed difficulty level to advanced and problems started.
Yesterday I encountered this guy : D'deridex Battleship in one of exploration system near DS9.
And I simply got ***** like 6 times in a row - I couldn't even pass trough his shields.

Finally I managed to feeding him with hargh'peng torpedos and stay alive long enough for him to pop from radiation.
Anyway - It made me take a look into my Boff and think about making better use of their abilities.
I just archieved commander level so I can fly heavy escort now.

So far my officers skills are :

Tac :
Tactical Team I, Torpedo High Yeld II, Rapid Fire III
Torpedo High Yeld I, Beam Fire At Will

Scn :
Jam Sensors I, Hazard Emiters II

Eng :
Emergency Power to Shields I, Reverse Shields Polarity

Could you give me some advice what can be changed here ? I'm going into cannon + torp setup for my ship.

For starters, you want to get 2 copies of Tactical Team I (TT) (don't bother with versions 2 or 3). With 2 copies, you'll have near-constant up time of Tac Team for damage and automatic shield rotation.

I wouldn't suggest using Fire at Will (FAW) in an Escort because, frankly, you shouldn't have any beam arrays loaded up to begin with. At most you may want one Dual Beam Bank (DBB) if you're running a Beam Overload (BO) ability, but since you already seem to have torps instead (you generally don't want both Torps and BO), you'll have more damage output with Turrets in your aft slots and Cannons (DHCs) in your fore slots along with your torp. You should then replace your FAW with another copy of Cannon Rapid Fire (CRF) to run those along side your Tac Teams at a near-constant rate.

The only other suggestion I'd make is replacing Jam Sensors with Transfer Shield Strength (TSS)--or, alternatively, going with Hazard Emitters I (HE) and TSS II.

Reverse Shield Polarity is a good ability, but you may want to try a second copy of Emergency Power to Shields (EPtS) in its place, as it will be available much more often than RSP is.

Thx.
Yep, Fire at Will is a leftover and I was thinking about with what to replace it in the first place.
And you're right about RSP, I took it because I read somewhere it is good skill, but now that I've checked it's recharge time, I wasn't good idea after all.

What about Polarize Hull instead of Jam Sensors ? Any opinions ?

RSP is really more of a PvP skill to have; so is polarize hull tbh--I probably wouldn't get them for PvE. Eventually you'll want to get a copy (or two) of APO, which will handle up on breaking tractors and such which Borg will throw at you, but you don't really need that right now. And you don't want to be hull tanking in an Escort at all, so shields tend to take priority.

APO = Attack Pattern Omega I presume ?

Correct

/10char