As a general rule, I do not think that players should make their character until they have played the game. Understanding the significance of the various condition effects or how well they play together goes a long way when you're selecting your powers. First timers will pick something not realizing what it really does.Similarly, with respect to the power choices, you can "hand" someone a premade rogue as easily as you could hand them a rogue in earlier editions. New players should probably not make their own first character, I don't think this is any different than past editions.
I really do think Ranger is the correct answer here. Give the new player a pre-gen Ranger (maybe an Elf, because Elven Accuracy is a pretty easy racial power to grok and they make decent Rangers).
IMO, the melee Ranger is easier to run for a newbie than the bow Ranger, because Quarry choices are easier for melee Rangers.
Give the character Twin Strike, Hit & Run, Dire Wolverine Strike and Jaws of the Wolf (the simplest Ranger powers, IMO) and you've got a character that is effective but doesn't require a lot of deep tactical thinking. It's essentially the sawed-off shotgun of the 4e world, just point it at the thing you want dead and pull the trigger.
The most difficult decision the player will have to make with this character is which encounter to use his Daily power in.
I agree that even the Ranger requires some inclination to think outside the "run to the nearest foe and attack until dead, rinse, repeat" box. However, the considerations you bring up (i.e. - run away when you're low on HPs, don't allow yourself to get flanked or surrounded by enemies, don't get backed into a corner, etc.) are things that don't depend on a lot of system-specific knowledge to understand and implement. They are more or less real-world, common-sense considerations. To me, they are materially different from some of the more esoteric aspects of tactical play that other 4e classes require (like the Fighter, for example, whose marking ability is really one of the less intuitive aspects of 4e's tactical play, IMO).Well, I'll add the player needs to understand the "striker" concept as well... this is not a class that should stand toe to toe with alot of monsters and expect not to have the glass canon effect. Though the funny thing is that, IMO, it is often the stand toe to toe character that most who want less complexity really desire. Instead the Ranger not only forces you to do round by round evaluation of the damage being inflicted upon ones character, but also to make judgements and evaluations on movement and terrain, as he must be careful not to get locked down by either terrain or an enemy or more importantly enemies.
But I also expect it to get better quickly, since most of them are quick to master new systems.