Voss pattern hull design and my beloved Defiant light cruiser launch bay carrier.

[CALiGeR190]

She is the beauty in the right row between her two sister light cruiser <3

She would really make the Imperial line up come to life!

I'm quite surprised she didn't appear by release... She was produced on the request of Battlefleet Gothic after all.
Endurance Class being an Armageddon conversion of the Endeavour which was suggested by Calixis.

Voss really knows how to make some good ship though! famed for their durability compared to alternate patterns (both in terms of armour and unconventional shield technologies)... bit of a shame that only the generic Mars pattern ships are in the game.

[CALiGeR190]

Ah thank you for honouring me again Lord Librarian!
If not the Defiant I at least would wish for the Battle cruiser pattern that has the macro's exchanged for lance batteries to make it a true fleet support vessel. I gave up dreaming about Jovian class because I have read in your ship profiles that only one of it exists...

You mean Armageddon? Well she's most common in Battlefleet Armageddon, (hence the name) as it was their idea to convert their wrecked Lunars into BCs... kind of rare, but not unheard of, in other fleet formations.

As for the Jovian, there are a handful with various Battlefleets. But that's because production only started fairly recently in the lore timeline, for the longest time there was only one.
During the Gothic War there wasn't even one of them in existence. Jovian was a Mars Class at this time serving with Battlefleet Gothic before being transferred to Battlefleet Baka after the Gothic War, where she got OMNOMNOMed to death by nids and rebuilt as her own class of BC.

Taking in everything into consideration though, at this point my heart longs for the Defiant above all else. Don't take me wrong, Dictator is nice, I LOVE Lord Solar Macharius, and the fluff of it, but I don't like it in this game as much (not saying its bad, I use it a lot, but I would prefer another tool... like... escort carrier Defiant >.< hahahah)

Well, like I said, it doesn't make much sense to not have Defiant in a Battlefleet Gothic line-up. Surprised she isn't here already, but I guess they just never got around to modelling her or they felt giving one faction three CL choices was too much... Enforcer was also used in front-line combat during the Gothic War (although that was out of a desperate need for more carrier than anything).
I'm most hyped for the Defender CL (basically a Dauntless Mk I with dorsal light-lance turrets).

[CALiGeR190]

With the battlecruiser I mean a carrier battle cruiser like Mars, that instead of the macro batteries has both broadside and dorsal lances in addition to the launch bays.

As for the Defender, does the dorsal lance replace the prow lance and what is their relative strength ratio?

Oh, Dominion? goof luck finding many of them outside of Battlefleets Baka and Tempestus. They weren't widely adopted due to them being perceived as failures.

And no.
Prow lance stays the same, it just has its dorsal Macro turrets replaced with 2 light lance turrets. So in game it'd be the Heavy Prow lance with 24 dmg per hit and the dorsal lances would do 6 dmg per hit (being the same things you find on Firestrom Frigates).

[CALiGeR190]

hohohohoho hohoho I like this Defender idea, seems like a pretty muscled light cruiser, could have a devastating sting against other ships of the line with collapsed shields, is this widespread used or?

It was produced to basically rape Pirates and escort ships attempting to attack convoy operations in the Gothic and Tempestus Sectors.
It's not nearly as common as it's cousin the Dauntless, but has seen plenty of service defending convoys. Most notable probably being Alien Bane: who destroyed 17 escorts and 204 strike craft in one battle defending a convoy during the Gothic War.

Doesn't say much about her effectiveness against larger vessels, but the triple lance strikes easily overpower other CLs and escorts, she fills her intended 'anti-swarm' role very well lore-wise.

Its a shame the Dominion isn't widespread, to me it seems like a very good ship as a head of a battlegroup, but then again after I recollect the Story of Lord Solar Macharius, it is better for a IN ships to be able to defend itself because they had to spread out quite often in their operations (Shadow Point) . I still would LOVE to have either Jovian or Dominion as my battlegroups flagship.

Sadly the setting of the game prohibits that.
Its before Jovian's time (well... before she became her own class anyway, you can rename a Mars 'Jovian' if you want, she's destined to lead her own class of BC) and Dominion was in production either at this time and is a rare sight indeed outside of their parent Battlefleets due to their perceived failures.

[CALiGeR190]

If you had to choose one ship you would have to serve on, what class would it be, why, and what role would you like to perform there?
After you answer I will too

Flag captain of a Dominator Class Cruiser. Best chance of survival.