Please note, I am not saying that a German Baltic fleet is a good idea, but if your going to do it, this is how I would pursue it and the reasons why.
G1: Purchase BB, DD, and 1 inf
Now why no carrier? Simple, the fleet i bought would give me another shore shot at 4, would survive the UK turn 1 air force, and would be good fodder against the UK fleet. A carrier grants very little extra offensive capability in any way shape or form, and is easily destroyed by subs, or subs +air, and limits my G1 attacks on the UK fleet as my planes have to land on it. I would also shuttle the 1 inf, 1 art to Finland on G1. This forces Russia to pull back on R1 and grant me my 3rd NO even if they do take Baltic States (which with 7 inf, 1 art, and 1 arm you should attack there R1 almost every game.)
G2: Choose.
If the UK went air heavy, purchase however many destroyers it would take to ensure they loose most of there air power, or an AC.
-This buys you more time against the UK building a fleet, and usually gives you enough time to have enough airpower to keep there fleet at the bottom of the ocean. Remember, UKs income goes down as the game goes on, yours goes up. They have 1-2 turns to get something going, then they no longer matter typically.
If the UK went fleet heavy, purchase a destroyer a round and possibly extra transports.
-This allows you to hold Finland, Norway, and Karelia for most of the game as you are shuttling up infantry while sending in tanks to reinforce. It helps you maintain good trades with Russia for most of the game as you use inf+air deep in there territory. Meanwhile, Italy has some breathing room and can help hold the Russians back in the south. Also, that fleet can latter be sacrificed with your air to sink the UK fleet when it becomes advantageous to do so.
The big thing is not to get caught into a ‘race to the larger fleet’ with the UK and to make sure Italy uses the extra time wisely. Now yes this opens you up even more to a KGF from the allies, but thats why japan goes hulk smash.