iMac is STRONG as in:
It won´t torn apart if you move it while it´s ON.. it won´t scratch the panel if you even use cheap cloth to wipe or clean the surface, as long as you don´t put sulphuric acid on it of course.
But then again, for Pete sake, you don´t need distilled or even lab-grade water to clean your screen, just use tap water and microfibre cloth. Cleaner solution may help to minimize spot occurance after your iMac dried.
iMac is VULNERABLE as in:
It dissipates heat just like normal computer should. If you put it in a warm room or not enough ventilation, the internal could be caput. The display could scratch ONLY if you use barb wire to clean it, or acid like I said. It´s just a normal glass, not hardened, carbon fibre reinforced nor bulletproof.
CONCLUSION:
iMac is just a computer, a nice computer indeed, but nothing really special when it comes to maintenance. Treat it well as a NORMAL COMPUTER should, and iMac should serve you well for years to come.
It´s not expensive as Ferrari, even if there is a slight or scratch won´t kill your iMac, unless you get defective component. It´s still a tool you can use well with proper maintenance
Why you treat your iMac as if you scared so much, as if you´d hurt her feeling. You´re not in some case iMac-fetish, are you?
So, why don´t you stop being neurotic, be normal, treat your iMac NORMALLY, clean it in normal way, use it, and maintain it normally, so people here can treat you the same way too. Seriously, you sounds like toddler. Ask this, and that .. another small this and that, you´re a mature man, are you? Don´t you dare to TRY NORMAL things yourself?
--- END OF STORY .. going back to my seat and enjoy my cookies, again ----