MichaelSomething
Legend
This is a very complex question and I'm not sure how to answer it but I'll try.
The first issue I would like to bring up is specialization versus diversification. The theory goes that if you put too many resources into doing one thing very well you won't be able to do other things well. See Crippling Overspecialization. You can be super good at attacking but what happens when a skill challenge comes up? Your defenses will be lower because you pumped your main attack stat instead of your other stats that increase those defenses. Evert feat that increases your to-hit could instead be spent on feats that do other stuff like boost mobility, increase healing, etc. There's a lot of factors that affect how well you do.
There are several factors that help minimize this. For one, in games such as D&D, it's generally better to specialize then diversify. You can focus on one thing real well and let your teammates focus on doing something else real well. Two, specailizing in hitting is a good thing. D&D assumes you'll be fighting a lot so being good at fighting means you'll be mostly successful in D&D. Three, it's harder to overspecialize in 4E. The system is built so that everyone can contribute more evenly.
To answer your question, could you define what exactly you mean by "too easy?" Is hitting with a "2" too easy? Is it okay to hit with a "2" every once in a while? I'm sure you can produce some monsterous results with enough splat books and time. For example, thanks to Martial Power, It's fairly easy to make a level 30 Warlord that gives +8 to hit when an ally spends an action to attack. If every player in the party used their action points for their level 29 dailies, then you can turn most monsters into paste. Even Orcus would be feeling that kind of pain.
Another way to think about this is to look at 3E. A character can be useless or all mighty depending on how well the PC can optimize.
I got to got to get to work though. I'll have to add more later.
