Exactly the point. A spellcaster with a wand can spam if the cost of replacing the wand is minimal. But the temptation isn't there for most folks because the class they're playing has better things to be doing with their resources. Bang boom pow.Patlin said:If you can call it a "temptation" to use the primary distinguishing ability of your class!.
The warlock's strength is repetition. The guy playing the warlock probably doesn't think of what he's doing as abusive, even when he's crossed the line. His reaction is likely to be "cut me some slack, this is my schtick".
When it comes to regulating risk-to-reward ratios, I think mechanical restrictions work a lot more reliably than an arbitrary "flyer-of-doom" method, which is basically an RP-based restriction. This is why I suggested that the more abuse-prone warlock abilities have some kind of built-in catch. Instead of being a standard matter of checking off resoures, the warlock would have to make a decision as to when he's pushing his luck too far.A Warlock (or other caster) who used charm with obnoxious consistency would be likely to see his portrait on flyers in many civilized area, and would probably be attacked if he was recognized.