Regarding Speaker handling power. I have been involved in speaker manufacture most of my working life. So may I give a little input to your question.
Firstly Speaker damage is caused in 90% of cases by an amplifier being overdriven into clipping. This is caused by overdriving an underpowered amplifier and also using excessive Tone Bass & Treble boost. It is better to have a larger wattage amplifier and use it with reasonable care than to have just adequate power used at a high volume.
As an example if you had a speaker with a power handling of 100 watts, it could be destroyed by an 20 watt amplifier being overdriven.
A larger 200 watt amplifier will drive a 100 watt speaker cleanly and with less possibility of damage if used sensibly.

Hope this is of help to you. Graham UK