Are there any tell tale signs to look out for in order to avoid frying a tweeter or blowing a woofer out aside from obvious sonic distortions?
You can also see if the woofers are bottoming out against the surround on some models.
Loudness sounds just like distortion - so it is sometimes difficult to tell unless you are familiar with it - most people think their stereo is extremely loud because ultimately at some point it is so badly distorting that it simply sounds perceptively extremely loud - 99% of the time it is not actually anywhere near as loud as you would typically hear music played in a nightclub or concert (where pro gear pumps out clean undistorted sound at massive SPL's).
A very small speaker like this is not going to play loud (concert level) cleanly no matter what you do - unless you sit only 0.5 meter from them.
The Dynaudios have a bass/mid that has an unusually large 75 MM diameter voice coil (for a 5.5 inch cone)!! This is rare in home speakers - it is very large compared to what you normally get in consumer hi-fi - I would call this a "pro-driver". Most people with 8 inch cones and some with huge subwoofers will be using voice coils no bigger than 2 inch and some will be using voice coils of a mere inch in diameter - yes - you heard me correctly - a woofer with a voice coil no bigger than a tweeter!!!
What does this mean?
Chances are your little Dynaudios will outperform most bigger floorstanders in terms of clean loud sound and clear undistorted transients - this is an expensive driver! A large voice coil will be both extremely powerful (big motor) and it will dissipate heat much more effectively than a tiny 1 inch voice coil (due to much larger surface area). This means transients are not squashed by thermal compression. (Thermal compression is of huge importance as you go louder - 97% to 99% of what you throw at a woofer is converted to heat - so you have a little toaster in there - small thin wires getting really hot - this plays havoc with reponse as coil resitsance rises and will affect the effectiveness of a passive crosover to boot )
You can probably get about 100 db SPL continuous cleanly at 1 meter with transients around 110. This is impressive for a small speaker. You'll need 200 Watts - something like a Bryston 4B-SST or a Krell or something that fits your tastes. This speaker is not an easy load.