For Angel Stadium, w/o a car, it would be cutting it close. We're at the stadium around 9.5-10. If they do walk out there, the easiest way is Katella to State College and vice versa on the way back. That walk is about 2miles from the resort.
As for the flags, the only time that's been an issue is the 2nd year either '07 or '08. We had red flags and by the time I finished it was a tad over 100. B/c it was red not black, the clock was still going. But if it were to be black, not really sure b/c I've never done a race where that happened. I know they did that for the Chicago Marathon a few years back, but don't know what they did aside from the flags. In the past weather-wise, the next couple of years after that, we had beautiful coastal fog and then since then ~ no fog. As for the temps, some say warm, some say it's okay, it's all relative.

The hard thing weather-wise is that it's CA and it could either be really nice or a heat wave could pop up, you really can't tell until race week.