This, for example, sounds like a good idea.
Well, I think it makes sense in that it is historical that India claimed these areas; you could have an event which fired for whoever owned them (usually Portugal and France) demanding them peacefully, but of course if either refused then India would get a war goal anyway because of the core. This would let an independent India fight anti-colonial wars against those countries.
My knowledge of India during this period is very limited so I cannot really make suggestions as to interesting focuses which relate to historical events or ideas. I think the current focus tree is actually pretty good, but it suffers as all older focus trees do in that as you guys make more of them you obviously improve, and so - at least from an ideas and content point of view - the newer ones tend to be better. This seems like a natural part of game development, though, and will be the same in other games' DLC.
I do think, however, that it needs some sort of QA pass. I have noticed a number of bugs in the tree, such as dockyard focuses attempting to place ports in incorrect states (so they are not given), and the Indian Gentleman Officers focus being strange, because instead of - like the Chinese version - giving all of your leaders (existing and future) an extra level in a particular category, it just makes future leaders start as level 2 generally, which is less useful.
I think it would make more sense if it was changed to add +1 logistics level to all generals; looking at the Chinese version (the Academy focus, which adds +1 planning), I think both the focus and national spirit need tweaking to do this, but it is a simple thing to change.
Also, the Assam Oil focus adds oil to the correct state, but requires that a different state (Bombay, I think) be controlled. Just a minor thing I remember from viewing the tree the other day. The Navy Funding focus has a text bug in that I think part of the custom trigger is wrong; it says "unlock light_cruiser_tech" or something, because that tech isn't localized. I think it needs a new or revised customer trigger.
A possible new pair of mutually exclusive focuses that tie in nicely with the new UK tree would be to decide whether - if you do the INC path - to become the Union of India, a full dominion like Canada and Australia, or the Republic of India, an independent republic with no shared head of state. Historically India and Pakistan in fact did both, being dominions for a few years until republican constitutions were ratified, but in the game there's no reason why it can't be a choice with different effects, such as political power, stability and different leaders and cosmetic tags. Just a small suggestion anyway... it's not important, but I think it would be nice to have, because it is in fact entirely plausible that India could have chosen a different route in the 1940s and still been a Commonwealth realm (with shared head of state) today.
Sorry for the long, rambling post! Just wanted to provide some feedback on the Raj.