1.- Drop Explo (which I assume you took) and keep Expansion. Then you want Quality, Eco and Quantity (this are a must) then Trade, Offensive and Religious/Inno. Since you are GB and your friends economy is so large I would suggest taking Maritime instead of Trade since he could overwhelm you with ships and land (aka game over). 2.- Stop focusing in the new world (gibe your CNs some subsidies to not die tho) and switch focus to India/Indochina. Since you are so small make TCs only in states with 2 CoTs if available until you get the merchant then just state everything else, especially if the provinces are good for deving. 3.- You don't need to push everything to the English Channel, by taking Cape you'll get 100% of the Asian trade and exclude HRE from taking whatever % he has in the English Channel. You want to become richer without helping him. 4.- Assuming you completed Eco, start deving. You ideally want 1/9/11 ratio for your provinces (reduce tax dev if you feel like it) but as long tax+production dev is 10 and mil is 11 you good. This is the most efficient use of your monarch points while also unlocking a new building slot. Said ratio will greatly improve you trade/production income (production dev gives doble income) and boost you manpower. When deving do it by state, be sure to use the dev edict, the state ideally needs prosperity, you want loyal burghers (for dev cost) and whatever else dev cost you can activate.

5.- As you economy improve you want to increase you advisor level as much as posible; take half cost advisors from events when available. Kill bad heirs (aim for more than 12 total points). Be frugal with your monarch points, as in don't take tech ahead of time, don't use harsh treatment, take monarch point from events, etc. All your points should go into Ideas, conquest, tech and everything left on deving. 6.- The buildings priority is the following order: Manufactories/Soldier Households (on grain, wine, livestock, fish), Workshops, Barracks and Regimental Centers. Marketplaces in CoTs provinces. Basically you want to boost your economy and manpower as much as posible. 7.- Start building heavy ships and always have them ready to fight around the homeland. Multiple combat width stacks around multiple sea tiles is ideal to prevent the HRE from sneakily landing. 8.- For your armies, delete all cav. Have stacks with combat width of infantry and a few stacks with full width artillery (highly depends on your forcelimit, but 2-3 is ideal, one to start main battles, second to initiate secondary battles especially on his reinforcements and the third stack to protect your reinforcements). More artillery stacks means you can start more battles and safeguard your reinforcements, but every artillery stack is one less infantry stack to reinforce battles. Don't be afraid to make big stacks (80k pure infantry reinforcement stack or 80/0/40 combat stack) if you have the manpower for it (which you should if built right); reducing micro greatly helps with reinforcing at the right time and also might save you from getting random stacks wiped.

9.- Go for the Diplomatic Hegemony. It might be tempting to take the Eco one, but I thing HRE will still have a stronger economy (I assume he knows how to build he nation since he formed the HRE). The Diplo Hegemony gives an insane 20% artillery dmg from backrow modifier, which will greatly improve your army quality. It also lines well with your build heavies goal to protect the mainland. 10.- AE and Governing Capacity are just numbers. This doesn't mean you can easily ignore them (a coalition can be game ending), it means you can ignore them if you are skilled. As for if you can actually survive, it depends on how fast you can scale your country with the tips I gave you and also how patient HRE is before he decides to antagonize you. Sorry for the long post, tho I still think I forgot some things. If you have any questions feel free to ask. -SkizzoSkillzz 2022