Not taking back London after a successful sealion is out of the question in my opinion. If the American forces are routed in Rome, than they are one and done.
1. Defend your Island, whatever the cost may be. I have tried abandoning London by spending early income on capital ships and transports in Canada, and I have learned that it dosen’t make liberation much easier. In my experience, it’s best to make Germany pay for England with large losses, even if you know you will lose your capital.
2. Don’t attack with Russia, build a strong line of Defence on your own Russian front. As Germany, I want Russia to come to me, because I just lost tons of units but I now have tons of money. Therefore, if Russia attacks German territories, the war of attrition will be on Germany’s door step where their new money is most effective. Make Germany buy units and come to Russia, the thinning out will help the western allies. If Russia wants to attack and make Germany weaker after sealion, I would limit it to Finland and Norway.
3. Move everything the Americans have to the Atlantic, I call this operation Albatross. When the US armada leaves the New York port, there will be nothing the US can do after that, and they should spend the remaining American income in the Pacific after that point. I had a blue print for that but I miss placed it, I may draw up a new one later. That massive force must liberate London to allow the UK to earn an income, and to take IPCs away from Germany.
4. Depending on how the board looks, I would fight in the areas you are losing, instead of building strength where you are already strong. Once you have london back, it won’t be long until you are even with the axis money, it will just take longer to surpass them economically. One thing is for sure, the Russians won’t loss Moscow after sealion (if played wisely) and with London liberated and a huge American fleet in the Chanel to support a weak England, the Axis won’t win on the Europe board. The only thing remaining, is to protect Sydney and Hawaii.