Once you add up the cost of satisfying all those requirements simultaneously, aren't we basically into the corporate-jet-rental price range? You've got stuff like NetJets serving that market.
I've never heard of NetJets before, but it looks like it's for big business only (since you have to own a fraction of the jet). I was thinking of primarily appealing to the individual businessperson market and use economies of scale to drive the prices down.
But that's pretty much the minimum price for any "show up and fly" program to be profitable. Also, keep in mind that this is price per plane, not per seat.
No problem at all. It would only cost you, well, a ridiculous amount of money, most probably several orders of magnitude more than what you are willing/able to pay.
By using small planes they can fly from minor airports (and city center STOL fields) or from the FOB section of major airports
That means faster checkin, quick TSA and no screaming kids.
A few airlines have failed trying to do this on transatlantic routes because the airlines/airports have a strangle hold on the big airports. The major airlines don't like competition and the airports don't like their richest customers speeding through without the opportunity to spend that 4hour checkin provides.
I bet a lot of people (mostly business(wo)men) would be willing to pay through the nose for a subscription service where:
a) You can just turn up and fly
b) You get true first-class service and food (à la Pan Am in its heyday), not what they pass off as first-class these days
c) Comfortable chairs with lots of legroom (they're most of the way there on this right now with first-class)
d) "Volume" subscriptions (just like with software) available for large companies
e) Relaxed luggage size/weight requirements
f) Good wifi and cell phone service (support for all major carriers) on-board
g) No children allowed
h) Frequent departures, using small planes
i) You don't have to go through all the TSA crap, both the screening as well as restrictions on what you can bring on-board
j) No silly restrictions on electronic device usage, including during takeoff and landing
The last two would obviously be near impossible thanks to the government, but the others are definitely doable.