I think the key is not so much removing material as in saying "you can only use this and this" as just saying "here's some stuff you can use, if you REALLY want to go muck up other options for youself, go to town." If the players are all new to the system and you drop a PHB1 in front of them, chances are real high they'll create a character based on that book. Later on they may well branch out, and they may even want to change a few choices they made at the start, but at least they (and you) aren't hit with a wall of stuff to think about.
Beyond that, 4e is really good about the DM not really needing to know all the player's stuff. Yes, there are a few somewhat OP possibilities, but they aren't ridiculous, usually require the DM to give you specific items, and can always be discussed later since very few of them pop up at level 1. You certainly don't need to know every power the players might pick up, or every feat. It isn't a bad idea to take a look at the player's sheets to make sure things are done correctly (for instance pretty close to every player that has ever joined my game has had their ability scores all out of whack when they showed up, lol). Beyond that you can just assume things are OK unless something comes up that seems wrong. Ideally the players run their sheets through CB, but that might not always happen.