Speakers Nominal Power handling/Amplifier

When you are playing with maximum limits, here are the rough over engineered rules:

1) Use PEAK power handling value of a speaker and the RMS value of your amplifier.
2) An amplifier should typically be rated at an RMS power value at least about 1.5 times the peak handling capability of your speaker. Otherwise clipping may occur.

The general rule of thumb is that an UNDER powered amplifier is much more likely to damage a speaker than the other way round (especially if the amp does not have any clipping protection).

A 10 watt amplifier will EASILY destroy a 200 watt speaker instantly simply by clipping. The reverse is less likely to happen since you will have a bit more time to react to the sounds coming out of an overloaded speaker and turn it down before it does any damage. Clipping can destroy instantly but overpowering takes a little longer which gives you a bit more more time to react to turn your amplifier down.

The moral of the story is not to push the limits of the equipment you have.

OP, People talk about the quality of the watts, too, so there may be additional options besides high sensitivity speakers. https://trueaudiophile.com/phony-watts/

Good discussion and advise Thanks everyone for taking the time and interest to respond. 
 All "expensive" audio products(amps speakers in particular )I would hope have some form of clipping protection. In fact, I would think any manufacturer making expensive gear would do this on behalf of their consumers to do otherwise is to disrespect their consumer's investment. 
 As for me my entry system in my listening space plays reasonably loud on 90% of my music. However, on a poor recording like Led Zeppelin's (CDs) I do find myself pushing the volume up. I never really was concerned with playing loud but protection my gear and maximizing resolution. fyi I'm just 2 meters away from my speakers in a well damped room. 

Your speakers' sensitivity rating means that a mere 1 watt of input will produce 87 dB when measured from 1 meter away under test conditions (in an anechoic space). 87 dB is already pretty loud, but every doubling of distance from the loudspeaker under controlled test conditions results in a 6 dB drop in the speaker output. Let's say you sit 4 meters away, which means you've doubled the 1m distance twice with a theoretical drop-off of 12 dB.  You're still getting 75 dB from a single watt, even with those "inefficient" speakers.   

Now, for some people, with some tastes in music and volume preferences, in some rooms, even 75 dB might be loud enough ... IF we assume we don't need extra headroom for transient increases.  But we cannot assume that.  You might need (or want) an extra 15-20 dB headroom to handle those musical peaks.

Every 3dB increase in speaker output requires double the wattage. Those transient peaks (or just cranking up the volume a bit) might call for 6, 7, or 8 doublings. So if your speakers are nominally 8 ohms, then you might want an amp with a little more juice.  But it really depends on many factors. You're already ahead of the game if you like what you hear and don't notice any clipping. More watts, per se, probably won't widen/deepen the soundstage.  For that, I've found that speaker placement has the biggest impact.  The trade-off is that, if you bring them away from the walls (on stands) to deepen/widen the soundstage, then the bass impact will drop off. To compensate, you might want to try a small powered subwoofer.  Meanwhile, if you are sitting closer to the loudspeakers, that should let you get by with a little less volume.

Hi Scott22!  Will low power damage your speakers?  You do turn the system off at some point in the day, right? Everybody needs to sleep sometimes. Do you worry if your speakers are safe while the system is off? Of course, not! Low power is only a problem if you are trying to play your music louder than the amp can comfortably provide. If you ask it to provide 150 watts, and it can only do 70, it will distort badly. The music will sound bad, grimy or grainy, obviously nasty; that should alert you that there is a problem. But very few civilized people run over 20 watts on a regular basis. Under 5 watts is normal, even with less sensitive speakers. 

You will get all sorts of advice (but you asked for it) on this topic. I have driven Magnepan 1.7i speakers with 9 watt Class Amps and had perfectly lovely music. Could they have played much louder, probably not; but, I didn't ask them to. You will notice that amps are rated for so much power at a certain level of distortion: 9 watts at 10% distortion, 200 watts at 1% distortion, etc. Notice that tube amps are often rated at higher distortion levels than solid state amps. Curious, eh? All this means is that all amps can produce more power that they are rated for, but they won't sound good doing it. You have heard PA amps produce ear splitting howls or buzzes when something went wrong, right? When that kind of thing happens, the tops and bottoms of the amps output flatten off when the amp produces all the power it can. They "max out." The sharp edges of the "clipped" output are full of high frequency energy that can burn out tweeters and even melt the glue that holds the voice coil onto the speaker's inner works. But this never happens under normal listening conditions. If your system sounds wonderful, plays loudly enough, and you are happy and don't need to entertain the entire neighborhood - just sit back and enjoy the music. There are people in the world who insist that toilet paper must be folded just so in order to clean properly. Smile politely at them, thanks them for their advice and do not invite them to dinner. Keep Smiling.