I can't agree with you here. A first level character with 2 at-will powers, an encounter, a daily power and a class feature is something I could explain to somebody in maybe 15 minutes.
You might be able to explain it, but that does not mean that the PC is easy to play for some people.
For example, my wife has been playing a Fighter for over 6 months now. She still gets confused between Combat Challenge and Combat Superiority. She also still sometimes forgets to mark foes. And she definitely has problems trying to figure out the best encounter power to use or whether she should use a daily power or not. And as she levels up and gains more items, feats, and powers, it gets a little more confusing for her.
So no, there are no good "starter" classes anymore since nearly all classes have similar numbers of powers and abilities and therefore overall similar complexity. The sole possible exception to this might be the Ranger who uses Twin Strike nearly every single round and that's more because TS is so good that even some encounter powers pale by comparison and do not need to be used often.
On the subject of weaknesses in the game, I think in their effort to simplify the game system, WotC actually made it more complex in some ways.
The most obvious way is conditions. Except for some At Will powers, nearly all powers, both monster and PC, throw some type of condition/effect out on the field. And conditions/effects do not end at the same time. There are 7 basic durations to end a condtion: save, end of target's next turn, beginning of target's next turn, end of user's next turn, beginning of user's next turn, end of encounter or when no longer sustained (or when a creature dies in the case of an aura). And there are other "condition-like" game status' like bloodied which add to this.
So in their effort to make the game faster, they actually made it slower in some ways by adding more bookkeeping.
Another way in which this complexity manifests itself is specialized rules. As an example, Daze. My wife might have her fighter flank an enemy with a Dazed PC ally, thinking she will get Flank and not remembering that dazed creatures cannot flank.
There are a myriad of little rules like this that although they are easier for rules oriented people who visit these boards and will read this opinion, are more difficult for people who just want to show up and have fun and cannot be bothered with reading the books or memorizing obscure rules.