I know of three times. The lowers are replaced at no cost to the user by Armalite.
Bad batch of polymer, user abuse, design flaw.
Yes. Not letting the upper drop free and slam open. Material issue can not be prevented
No, but it is replaced free of charge by Armalite no questions asked regardless of warranty.
See above.
Due to the infrequency of the pivot point breaking, it really isn't much of an issue. Also, the customer service and replacement solves this problem if it ever happens.
For those calling this a bad rifle, an AR15 wannabe, or a poor excuse for an assualt rifle, I just shake my head. It never was supposed to be an AR15. It never was an assualt rifle

. It's a cheap .223 semi-auto. Trying to make it more will only leave you disapointed.