Yes it would. The thing has FP4 WBs, Str 3 BCs and THs. It is a gunship already but not as efficient as the IN contemporaries. To give it Str 2 lances, it would now be a much more effective ship rivaling a Dauntless which has FP4 WBs and Str3 lances.
And would not have rivaled the slaughter which is, again, the ship they would have weighed it against. Stop trying to use modern IN, it's not fluffy in this case.
Yup. System ships which the current SC and Escorts can easily handle. Establishing moon bases which do not require lances.
I'd say that the common SFD Monitor is being heavily underestimated here. +6 and two shields and turrets make a single monitor a tough nut for a SC or a nova to crack. One on one, a nova killing it is nearly impossible, and they cost within 10 points of each other.
Yup and if they find a Chaos task force orbiting the planet? Should they charge in headlong?
It would not be the first time they did exactly that. Particularly the Minotaurs and the Space Wolves.
And so we present other profiles like all launch bay BBs and SCs. Maybe torp heavy. Those are different weapons which do not have to have lances as part of the package. Doctrines and tradition would mainly be how they like to handle things. Some prefer assaulting (boarding, hit and runs, fighting up close) while others like siege tactics and bombarding from afar (which WBs and BCs are well suited in doing).
Torps are anti-ship weapons, having no use in planetary landing support, and by your logic, prohibited. BCs, at least for SC, are not a long range weapon, and are unsuitable for what you describe.
BCs are also powerful anti-ship weapons. A lance only inflicts a critical hit 1/6th of the time, a BC does 50% of the time. Since a critical hit represents massive internal damage to a ship...
"Bombardment cannons are equally devastating in ship-to-ship combat, capable of blasting apart any capital ship in just a few salvoes." Armada, Page 21.
Nope, it does not. Yes, the lances make the ship a threat against another ship. The only thing that can minimize a lance's damage are shields. WBs and BCs are affected by BMs, shields and for the former, armor values and both are subject to the gunnery table. Torps and AC while ignoring shields are affected by armor value and can be shot down by turrets and AC. NCs are affected by shields only as well but it has it's own problems in the scatter rules as well as not being able to fire at anything under 30 cm.
So lances are what makes a ship truly a threat against another ship and is a central component of what really makes a ship a proper gunship.
So, the Avenger is NOT a proper gunship, and not a 'true' threat to other ships, because it doesn't have lances, despite having a more powerful broadside then a Retribution class battleship?