Great pointers above, thanks for sharing!

I recently started a GB-campaign myself (H/H, but switched battlesettings to M quickly) and have made some real progress in the american theatre. Here are some random tips that might be helpful:

* The british navy is, much like it was historically, your backbone. Sure, you'll need a few armies on land here and there to take provinces but to reach your global goals as Great Britain you'll need a strong navy - or ten. My advice is to have at least one strong fleet (relative, depending on the opposition) in each theatre. Personally I've avoided war with the european nations and let my allies Austria and United Provinces down in quite a few conflicts just to avoid naval wars. This way my ships can make it to trading zones quite easily. When you do get into a war with France and/or Spain you can keep the upper hand from the start if you first destroy all their navies, and then blockade their ports. That way you'll also bleed them dry, since they won't get any tradeprofits from their colonies.

* Pirates can be a real nuissance for anyone, and as the british you have the pleasure of starting with two regions (Jamaica and Bahamas) close to their two home regions. If you want to gamble you can leave them be and hope that they do more damage to your enemies than to you. I was so annoyed with them myself that after a few raids I put together a large navy in the Caribbean ocean, beat theirs to a pulp and then landed forces on their islands and let them sleep with the fishes. Coincidently the french have a nice settlement (Martinique, I believe) in between the Pirates two islands so if you're already at war with France you might as well grab that region while you're at it. This way you have three dependable islands that give you a steady income and ports that let you send tradingfleets to the brazilian coast in just one turn.

* Mind your alliances - if you ally with some bloodthirsty nations like Prussia or Sweden and heed their calls for aid you may find yourself at war with half of Europe in a few years. At the start of my campaign I was sorely tempted to ally myself with either of those nations (protestants unite and all that) but I was quickly dissuaded as their list of enemies just grew. Playing on Hard settings for the campaign it seems all but impossible to get good deals diplomatically without wasting a fortune, so unless you have a good plan I'd advice against trying to get more alliances.

* Trading is your friend! The AI can be a bit slow on sending indiamen to the tradingzones (or at least it has been in my campaigns) so if you send out a decent fleet before 1710 you can grab a majority of the tradenodes in Africa and Brazil. One tip is also to send out a rather large fleet from Europe to get rid of any hostile fleets in the tradingzones, also clearing up the tradenodes in the process. I strongly suggest you don't go to war over a tradenode though, so if a neutral nation that you have no other intention of fighting is holding one or two nodes I wouldn't attack them. Unless they're a feeble minor one, of course
Trade agreements are extremely profitable if you pick them wisely. Maratha Confederacy, Russia and Sweden seem to be the most profitable, while UP and the poorer minor ones are the least profitable. Just make sure you upgrade your tradingports and keep your traderoutes as clear as possible. For instance in my campaign I get 14 000 each turn from trade, so if an enemy fleet blockades my biggest port I lose around 10 000 just that round...

* Peace and trade with the Barbary States. This nation can be a real pain in the mediterranean for any nation. Personally I managed to avoid this by haggling for peace with them (cost me about 1000 coins) and then making a trade agreement for the same cost. Totally worth not having your trade routes raided, in my opinion.

* Don't underestimate the indians! Sure, they have terrible buildingoptions and a predominantly melee army, but they also know how to use it to their advantage. I have made the mistake of underestimating them in a few fights and it has cost me dearly each time. Be prepared to see them rush your lines quickly and have some tactic to counter that. You will want to get the bayonets (at least ring) upgraded as soon as possible if you intend to go against any indian nations (which you of course will). Oh, and in case it hasn't been mentioned before make sure you destroy their buildings when you capture their regions, since yours are better.

Hope this helps a bit!

Kind regards