Hey, you're only level 40, I would recommend getting a second BO, take him down the gunship line and lvl some more supports in the meantime.

You'll be a killer in Tsukikei with your gunners, ditto Mogami. Nearly-blocking Mogs with decent reload is a horrible thing to meet in Blitz, so if that's your thing go for it!

Alternatively, get hold of a Yubari and snipe away (also in Blitz).

True the Kongo isn't great but the grind is quite short and I think I'm right to say you get an XP bump for being in a BB.

I hate AA-ing but I never found Blitz particularly horrible to lvl in (I have a crew lvl 72, and 2 more near lvl 50). I think if you focused on having fun you could really enjoy Blitz even if you lvl slower rather than targetting faster lvling, because that's missing half the point of the game. Being king of the small guys in a good CA is very satisfying while it lasts =P =P