Pick a mistake. It would have wiped out any other company that didn't have the equivalent of MacHeads, those do or die "it's ok, Steve, we forgive you (again)" crowd.
Design flaws aside, the Apple /// probably wouldn't have succeeded anyway, because Apple's counterculture image made them unappealing to the business market. That and the /// was a 6502 machine, and thus couldn't run CP/M. Commodore's business computers also flopped (in the US, anyway) because they were 6502-based.
As for the Mac, it only began to turn a profit in 1987. During 1984-1986, it was the good old Apple II that brought in the money.
Then of course, Apple nearly expired in 1996 when the Mac line had become stale and Windows 95 was being promoted aggressively, and it took the return of Steve Jobs to save them.