The standard recommendation for the Aeropress, including from Adler himself, is to use 175F water, much less hot than you'd use in other preparation methods.
In Seattle at least, there is near-universal consensus among every coffee shop I've been to using an Aeropress that 175 is much too low. Most go closer to 200.
What’s your definition of “proper”? You get a different flavor profile if you vary the water temperature. My favorite for single origin light roasts is very fine grind, not too much 170–180° water, and short steep time. It requires somewhat more beans to get strong coffee compared to a brew using more, hotter water and a long steep time, but the resulting cup of coffee is much tastier IMO.
I have an early one, use it a lot (near daily for years), no cracks (only issue is the rubber plunger head pops off often when removing). Those with problems, can you indicate which material it is? (BPA, BPA-free, translucent gray, big lettering on side, etc.)
Had mine for 3 years now. It's looking cracked/scratched, but still works just fine. Not bad for £25; I'll buy a new one in a heartbeat if/when it breaks.