Can you overpower a speaker

I haven't heard an amp in bridge mode sound as good as it doesin its normal mode.Then there's the other minus like Stanwal brought up.An amp that could run at 4 ohms continuous,will only be capable of 8 ohms continuous,in bridged mode.As far as having to much power,its what you do with the volume control that matters.If you hear the least bit of something that is not right,back the volume down.It's real easy to blow speakers with an underpowered amp.An underpowered amp can go DC on you and feed the power supply voltage to your speakers and fry them.

You do not need to over excursion loudspeakers to cause damage to much power can cause voice coils to melt they are dam close to melting in most conventional loudspeaker designs to begin with. So doesn't take much extra to cause damage. 100 watts into most any transducer is or near causing a melt down in voice coils. Most VC use glue this can melt before metal, hot cool cycles will eventually cause a open circuit since coil is broke no connection. I have seen this damage in modern loudspeakers far more than any other type of damage except physical ie drop smash cones pushed in.

Let me ad this.I should have also said to much power can fry your speakers to.Not just to little power.Again,keeping the volume set where you don't get any distortion,or other sounds coming out of your speakers,that sound wrong when you start playing them to loud.When something starts sounding bad,back the volume down,until it sounds right.

How about this option: Get a pair of killer subs. If you use them with a high quality crossover it will alleviate a ton a strain on your amp (since bass is power hungry) and help to protect the speakers from being pushed too hard. A huge pair of REL's will give you all the bass you could ever want, protect your speakers and add hundreds of watts per channel...

There are ratings for reasons;answering you question on wanting massive power in my opinion is fine if applied properly and understanding the consequences if used improperly.