It is diffucult to answer as they have diferent play styles i would suggest not buying the dunq because at level the spread is horrid. even with super vetted elite acc gunners.

The good thing is that you can try any ship u can afford and then if you dont like it just sell it you dont lose any or much creds when selling.

and if gaining creds is a problem make a cv crew = ATM.  

Answers to your questions:
1) Dunq is good but it's a PBB, so you buy it with Olives, not credits.

2) Just buy any CA you like, with credits, because when you sell your CA you get a full refund of credits. You lose your credits when selling guns (not sure about engines/radar), but this amount of credits you lose is negligible. DO PAY ATTENTION to remodelling, because the remodelling cost is not refundable. Therefore, I do not recommend you to remodel your York to Surrey, but you can remodel your Renown to Repulse, and KGV to POW. 

3) If you get your Dunq, stick to it until BB3 or BB4.

4) If you are a relatively new player, I recommend you to go Revenge BB line (and then choose L1 instead of Vangaurd) because Renown (crap in GB) / Repulse (lack of firepower) / Nelson (no scout and usually first target of enemy CVs) die too easily in GB.

Firstly, thank you both for your answers.

On the topics of Jedizorro's points,

1) Yeah, I was aware the Dunq was a PBB, although I am unaware of some details regarding that - I found a website telling me that they're bought, not rented, but it also listed a cost - having purchased a premium ship with olives, do you also have to buy it with credits?

2)Both of those points are fantastic to know, so thank you.

3) Got it.

4)Thank you again for the insight. This account is new, although a few years ago I played on NFEU with only 4 nations and subs were being introduced as I stopped. I remember having a PoW and a German CV, possibly a Seydlitz, but I don't think I ever got to a Nelson :/ Nonetheless, I suspect your point refers to at-level gunners/supports, so yeah, I'm new! 

Premium ships are received through the item tab (the red tab at the top right of the screen while in a harbor) after you buy them. They require no additional expenditures for the ship itself, and come mostly outfitted already. However, they may not have the best choices on some components, and additional or alternative components are bought and sold as normal. Premium ships can be sold for credits and points, but it's not enough to really be worthwhile to do so.

EBBs and ECVs are acquired the same way, but come with no components, just like ships bought from the shipyard. Higher level ones actually can give decent returns for selling them, but I suspect the days of easily getting EBBs in large numbers may be over, which is mostly a good thing.

Edit: Also, I'm seconding the Revenge line, as it has the easier ships to utilize. The Dunk really isn't impressive until you have a BB3+ crew, though at that point, it does offer a decent alternative to the KGV/POW. The Renown line has what are probably better ships, but they require skill and a good crew to make use of. As such, I'd rate Revenge line as Normal Mode and Renown as Hard Mode.

dunc can be worth persevering with... you ll see 120 players use it at times..its even better then

dont use acc gunners at all in UK line thats covered elsewhere..you have to put up with poor spread at 60 ..but it gets better and so does the player as you level up..

dunc  has range very manoeuvreable not a huge hitbox and plenty of support slots ..

you buy it once and keep it for as long as you are in the game...

its playstyle leads onto L1 front guns  L2 front guns .POW front guns (or Hood a la Jedizorro  ) ..

If you are going to play front and rear guns its not so useful in that I reckon its better to learn slingshotting before you develop other bad habits!! 

Good slingshotters are generally good players in this game ..other thing is join a fleet...they will help you a lot if they are any good


You could take 1 BO up the cv line and put your gunners in the R slots ...plenty of points credits and high level gunners when you start the BB