Driving 1 ohm

" am I slowly damaging the amp without noticing it ?"

Not really - you do put some additional stress on this amp but if it did not failed during initial period then it was designed properly to deal with the stress so enjoy and don't think about it. If you amplifier will ever fail it will be due to lightening or other 10,000 reasons why amplifier cam fail.

Good Luck
Simon

It depends on how loudly you play the amp.

Thanks Simon !

Rwwear, not very loud, we can still speak at normal level while playing music. Most of the time, below half the volume dial on the preamp. But.......even at a moderate volume level, on good recordings, the bass level will drop at a point that a vibration sometimes continuous, can be felt. Those speakers are really something else now. And it is specifically that kind of effect that makes me cautious about the amp.

Well, depends.
Ask CJ if your amp is rated down to 1 Ohm &/or meant to drive 1 Ohms loads. Most amps in the market are not & even if they are, they sound like crap!
If it's rated down to 1 Ohm & meant to drive 1 Ohm then CJ should have provided adequate heat-sinking & an able power supply.
Otherwise, the amp would clip & the power transistors would saturate thereby degrading them over time.
Further, there are 1 Ohm loads & then there are 1 Ohm loads. How benign is your 1 Ohm load? Is there lots of phase shift in the 200Hz - 8KHz region? If yes, then your amp is being pushed pretty damn hard. If there is minimal phase shift, say, 10 degrees, then your amp is not being pushed hard. It's still driving a very low impedance but it does not have to provide too much power/current to drive the reactive load in the speaker x-over.
The amp-speaker interface is dynamic over 20Hz-20KHz so there is no fixed answer - all depends on how "nice" your speaker is being to the amp. Plus, as Rwwear pointed out, how loud you are playing your music.

Check out FM Acoustics line of power amps.