Most of the FR NPC's have died of old age in 4e. Drizzle's still around, but his other adventuring companions have passed on. Greenwood's Gandalf is still alive and crazy as you noted (and I don't think they can ever kill him off while Greenwood lives), but almost all of the other Chosen are dead.
Those two characters are the top 2 reasons I never ever play in FR
Forgotten Realms backgrounds are no more powerful than Scales of War backgrounds. FR and SoW backgrounds are really the only backgrounds it makes any sense to have - the other, generic background format serves no real purpose. It would have been better to just say, "Every character can either gain a +2 to any skill or make any skill a class skill." FR and SoW backgrounds actually let you use a background to customize your character, which other backgrounds do not.
I have quite opposite experience. Yeah, I am using PHB2 or other backgrounds as just examples (and actually, they are). When I DM, I just tell my players to make up background stories of their PCs, then either make one skill into a class skill or have +2 bonus to one skill. It is working perfectly. Encouraging players to make their character more alive. Be more creative and imaginative. And when a player can't think of a good one by himself, picking up one shown in the book will give him a shortcut. Some of the players are not good at that kind of thing and that is fully acceptable. On the other hand, generic background rule is indeed good enough to either compliment a character's or party's weakness (say, paladin lacking athletics skill or no one in the party is good at nature knowledge roll) or strengthening one's speciality (say, having really high perception skill).
Another problem of FR backgrounds is that many of them are tied to certain area of Toril. If a DM want to use not-so-well-supported part of Toril as his adventuring ground, players will find that they cannot have background as strong as those regional backgrounds. Also, the very existence of regional backgrounds discourage players to choose their PCs place of birth freely or from RP reason, as coming from a certain region makes his PC stronger. That is really annoying.
Regarding Scales of War backgrounds. SoW is just a campaign, not a full world setting. Those rules are meant to be used when and only when you play that campaign. So comparing those rules to rules in big world settings are inappropriate IMHO.
And as for campaign settings that have power creep in their rules... I'm guessing you've never looked at Dragonmarks or Dragonshard Augments from Eberron, or you wouldn't be complaining about FR power creep. Those Eberron elements are more powerful than anything the FR setting brought to the table in 4e.
Some of the Dragonmarks seem to be very strong. But if you use them in Eberron campaign setting, those are tied to very interesting background story of the world and also restrict PCs in some way (socially, or for RP purpose). Eberron is different from standard "medieval" or "dark age" like fantasy world. That is a much modern world in witch social relation are more important. So IMHO, as long as we play in Eberron, with dragonmarks, we can have different and interesting gaming experience. If we are using different world-setting, it is something better banned by the DMs. Regarding Dragonshard Augments, I am allowing PCs to buy them, and having no problem at all. Those magic items are useful but not uber-powerful comparing to magic items of the same level.
And, as a world setting, FR is, and always has been, just "another fantasy world". That has been the biggest and the inherent problem of this world setting. Why on earth do we need another fantasy world, which is basically not significantly interesting nor different from plain sword-and-sorcery world at all, but with not-so-well-balanced-against-core rules? Because you can make stronger PCs in that world? Bah! If the alternative world is different and interesting enough like Eberron, Darksun, Ravenloft and such, I am interested in. But tasteless FR? Just because that is the world of well-sold novels? No way!