I personally completely disagree in strategy. I dont fight Scotland outside of perhaps a Humilation war or some other similar causus beli (for valuable power projection and prestige), and as a money farm. No need to sit on Scotland till you form GB- a wasted Diplo slot, as their armies wont make it to the mainland. Instead, I go about doing three things
1) I immediately vassalize one minor in Ireland. They can have all the Irish provinces so I dont deal with revolts-the Irish are usually nasty and not worth the unrest or accepting thwm till you have em all. If Scotland allies a minor, great- continually break their potential alliance with France and force them to relase the Gales- you can reconquest it for them later.
2) I support the Independence of Sweden. The reason is twofold- it allows you to weaken what is likely your 2nd or 3rd biggest rival and only comparable Naval power in the lategame (+50% naval force limit is damn strong) and allows you to take a provence in Scandinavia. From there, fabricate claims and use threaten war against Norway and Sweden as often as you can
3) Either vassalize or get a PU over Britianny (it happens suprisingly often) then do the same to Province (if they still have Anjou, its easy to do so). This gives you FAR more power on the continent, and enough troops from your vassals to actually fight France.
From there, the midgame strategy emerges- by then, you probably cant get a PU over France anymore (or you fought and won in the surrender of maine, or ended up with that mission I rarely get). Break up france unless you have a PU, only taking a few provinces from them directly. Either vassalize or threaten war against the minor states that emerge from a shattered France.
On to Spain, hope that it doesnt form. If it ever does, get a PU over Portugal. Or something. Anything. If you can actually fight spain, force them to disintegrate as much as you can. Until then, support rebels (especially those in Aragon/Catalonia) and build up economic power in Itally (by threatening war against Itallians after Shadow Kingdom, and vassalizing anyone you actually war, because annexing will get you a coalition). A no CB war to get into north Africa will help you in this cause- a strong vassal in the form of Tunis or Morroco can usually do a world of difference against Spain, who is the PRIMARY rival in the mid and lategame. Also, take Iceland. You need it to beat spain in the colonization game.
Your strategy works perfectly well, especially for begginers, but mine is probably the easiest way for a beginner to blob as England, instead of just play passive (which most beginners dont have the patience for. I didnt)