Note that all of my opinions are on the basis of PvP. In the end, with Perfect World owning Cryptic now, PvP will begin to become the center of the game's endgame content and will be the denominator in ship design and balance.
That said...
Oh, I agree with you on the cannons (note my post didn't even touch on it).
If I had a problem with that, I'd have stated it.

I'm not bashful.
On the lance... I'm not saying it isn't a horrendous idea altogether, let me get that out of the way. It's a sound proposal.
For any other ship BUT the Galaxy-X.
First flaw... 3sec or so recharge, with each blast taking 30-40 off your Weapon Power (not including other weapons).
This suggests the ship, even run by Tactical officer with fundamental increases to weapon power, will be almost constantly running at a MINIMUM of 40 less Weapon Power.
You would need 2x EPS AND be an Engineer just to compensate for that drastic, that rapid a power loss.
Huge waste.
Your sustained DPS would be completely shot after the first volley and you would be a sitting duck. I'd be able to throw rocks at enemy ships and deal more damage at that point.
Second flaw... You KNOW the ship's maneuverability is an issue (more-so for the less-experienced Galaxy-X Captains). Maintaining sustained DPS with this ship over long periods of time is unrealistic.
This ship is not designed for that, and to try to turn it into that would be trying to take the Escort role out of the game, and the Galaxy-X's beauty out of perspective.
Galaxy-X is a genius monster of burst damage, not DPS.
What's the difference, you may ask?
DPS = Damage Per Second. The amount of damage one can sustain on enemies over a period of time. This does not have any bearing on per-hit damage, but rather how much damage can be inflicted overall and over time.
Burst = Instantaneous damage. The ability to cause an enormous amount of damage in a very short amount of time, almost instantly, so fast that the enemy doesn't have time to react.
The Galaxy-X is built for Burst, and is TREMENDOUSLY effective at it.
Have you ever tried decloaking on an enemy's broadside, tractoring them, applying about half a dozen Tactical damage buffs, and unloading Lance with a Tricobalt?
NOTHING can survive... you'll deal about 130k damage easy if your build is correct.
Then, your burst will be on cooldown. Now, your responsibility is to use your engineering abilities to survive and support your allies, while using your many weapon slots to maintain constant focus fire on enemies you want to pressure, combined with allied DPS.
When your lance recharges, you're ready to instantly kill another target without a chance of being stopped.
THIS is what the Galaxy-X excels at. Your proposal takes that fundamental usefulness away.
You turn this incredible beast of war into a mockery of an Escort, stripping your ability to support your allies between bursts because you'll be too busy trying to manage power settings and damage enemies with what has become an inferior weapon.
Due to the ship's maneuverability, such a weapon is impractical.
However, the way the Lance is now, that one time you get your nose fully about on an enemy is all you need to win.
For what you propose, the ship would have to move like an Excelsior, and have 4x EPS Flow Regulators. That won't happen.