It's been commented that many changes in the way 4e abilities work was to keep the DM from having to play the monsters stupid -- because otherwise the wizard is toast first round and there's nothing the players can reasonably do to stop it.
Both the powering up of PCs and the changes in monster design were intended to increase balance in combat. By the same token, it's not good to expect players to play their characters as stupid -- if they've got powers useful out of combat, they will use them out of combat, as often as they can. The DM -- and the world -- need to account for this.
Sure, easy enough. Moments after the PCs use their powers, they are assaulted by those (insert group of people adventurers generally piss off) who've been following them the whole time, waiting for them to blow their abilities. Roll inititiative, and oh yeah it hasn't been five minutes. . . good luck. Of course, that's metagamy on the DMs part, but I've done similar things to show the PCs now and then that bending the rules over a table and having your way with them will only lead to tears. Not something that I like to do, mind you, but misbehaving players who like to look for rules exploits and "game the system" deserve it, IMHO.
Or I could save my time and, like Hong suggested, throw dice at them.
The PCs won't be the first with such powers in all of demi-human history, and towns, cities, and nations have all learned to account for them and act accordingly.
Really? Says who? Maybe big towns and cities, but podunk villages? Not so likely. just because something has been around for a while doesn't mean that people will automatically figure out how to counter it (effectively), otherwise sickness, violence, mental illness, and criminal activity would have been gone long ago from our world.
Just as suspect 3e casters are bound, gagged, and roughly woken every four hours, all 4e characters will find there are precautions taken against them, whether it's dark pit cells with no LOS to anything, magical chains of force which can't be broken by martial exploits, or what not.
You're assuming that this will always be the case, that a PCs captors will have access to these inventions or even know, other than on a very basic level, how to deal with the PC's. Keeping them from getting rest? Binding and gagging? Sure. But where are they ordering the magic chains from? Did they just happen to have them on hand? Do they just happen to have a lightless chamber in town to deal with the huge influx of Eladrin criminals that must surely be plagueing them to make this necessary (and economically feasible)? Or would they most likely just consider that an eladrin criminal who *pops* away is resisting arrest and is therefore to be shot/attacked on sight next time he is seen? Could there be cities equipped to deal with such things on a magical level? Sure, why not? I just don't find it realistic to believe such methods are available in all places at all times.
Because you heal fully in 6 hours, traditional battle tactics of wounding enemies to drain a foes resources caring for them are out; all combat is lethal and you don't leave any enemy soldiers alive if you can CDG them.
Sure, and as a DM I remind the players that their mercilessness in dealing with enemies will create a reputation for themselves such that if they are defeated, they can expect the exact same treatment. Hope they like rolling up lotsa characters. However, less draconian characters may find that their enemies don't always CDG them if they don't present themselves as bloodthirsty beasts. Heck, even the bad guys can have a sense of honor, and not everyone feels the pressing need to chop all the enemies into tiny pieces (or may even have the time to waste). Plus going around the field offing downed folks, I would think counts as part of the same encounter. . . so while they were messing around defiling corpses the reinforcements have arrived. . .
Because 'minions' die from any damage, low-damage traps (cheap to make) surround outlying farms (and alarms sound so you can intercept the non-minion kobolds which survive). Etc. Things like this make the world feel believable -- and if you don't believe in the world, how can you have fun pretending to save it from evil?
Do minions have signs on their chests saying they're minions? So some kobolds die from the traps, and some don't. Its very metagamey to say that since my trap only does one point of damage(a metagame concept) the survivors must be "real kobolds". Characters aren't able to apply the math of the D&D universe in their heads like that, or they're gaming the rules, and not playing an RPG. Heck, I might well make kobolds with variant (but low hit points) to mess with the individual who would try to pull that off.
Fortunately, I've rarely had to do anything like what I've mentioned before. Most of my players are great, and the ones who exploit the rules are no longer in my group.
Frankly, there is NO system on the intricacy level of an RPG that isn't going to have some loopholes. That's what a DM is for. The system doesn't have to be perfectly inviolate to be a good one.
Of course, this is all my observation of what you percieve to be an issue. And perception is king in most ways of life. If its a bug for you, then I gues its a bug for you, but I think much of the grousing here is overwrought and, purely, a matter of different tastes.