Unfortunately, those things you like are inimical to 4e's design. 4e deliberately scaled back on options for strategic planning and for player empowerment.
I agree with the first.
I disagree with the second. Player empowerment in many ways is at a greater level than it has ever been. For example, the number of options for the development of each PC is much greater than 3.5 ever was. PCs have fewer charged items and spell casters have fewer spells, but the sheer number of options overall has increased.
4e wanted to move the power to establish the narrative structure for the game back firmly into the DM's hands. Allowing the players to purchase items that "let them have 15 encounters in a row" is nonsensical in 4e's paradigm.
What do you consider the narrative structure of the game? To me, it has nothing to do with whether the PCs have 3 encounters in a row or 15 encounters in a row. Unless he has some type of time based encounter layout, why would a DM care if the PCs got through 4, 6, 8, or 10 encounters before having to take an extended rest? With unusual dice rolls, the DM's plan of a 7 encounter day could end up being any of these.
If there's a need for 15 encounters in a row, the players and DM should be collaborating on a way to explain that.
Why?
The number of encounters per day is merely a metagame side effect of how the rules were written and how resources are typically used. It should have little if any in character correlation.
PC Warlock: "Remember team, the world revolves around 5 encounter days and this is a pretty big place. At least 200 feet by 200 feet. So, be prepared to be in here for 3 days."
Err, huh?
And, there are a lot of literary and even real life examples of heroes fighting for the better part of an entire day. Why is 15 less than one minute encounters in a row (or a day) so astonishing? It's only because that is what the designers limited the rules to.
Being "prepared for any scenario" is another way of saying that you have the ability to bypass encounters that were meant to be challenging.
No, it means being prepared.
If my PC crafts a Potion of Water Breathing and another PC doesn't, it means that my PC is prepared to go underwater for an extended period of time and he isn't prepared for that.
It doesn't mean that it will allow me to necessarily bypass an encounter. Course, a Potion of Water Breathing doesn't exist in 4E.