I understand that, the beauty of having a ton of headroom though is that you run less of a risk of clipping your amp with dynamics...
I really doubt you will pop anything with such little power. If you do, then maybe you should look into another hobby //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif J/K..
If you want to protect your tweeter, add a cap in series with the positive end of the tweeter terminal. Something between 20-30 micro farads should be fine...this will add an additional crossover between 1.5-2khz should your highpass filter fail...
parts express has them...