If you have any interest in eating at Hollywood and Vine, try to get an 8am ADR for a day the park opens at 9am. We did this a few weeks ago, and it worked perfectly. We were done eating and seeing characters by 8:40, we hung out for a few minutes because it was raining, and headed over to the sign-ups around 8:50. The park was already opened so some people were already at sign ups, and we got in line. We got into the 10:10 training. There was no worries about being at rope drop or if we were going to make it into the training.
Also, if it's raining, or forecasted for rain, try to pick a time of day when you don't think it's going to be raining. Like I said when we signed up, it was slightly raining, and luckily we got into the 10:10 class, and not 9:20, because that one got cancelled. So if it's raining, they will cancel it. They give you a choice of when you want into the training (from whatever they have left).