I have a question about the way competitions are run.
Is it the usual practice to tell dancers, in advance, the running order of competitions. So that they know, for example, that event XX will be danced immediately after the amateur 5-dance event.

Usually you know what session you're in in advance, because a rough schedule is given with the sign up paperwork. When you get there, you can buy a program which gives the specific order of the events. Does that answer your question?

In other words, if you're dancing Novice Standard, when you sign up you'll see that it's scheduled on Friday night. However, you don't know what time on Friday night. So, you get there and buy a program, and you see that it's the 10th or so event that night, to be danced at approximately 10:00 PM. You then know that you have to be in the ballroom ready to dance by no later than 9:30 (although, I'm ready long before that).

I can add that at local events I've emcee'd I'll request different events to begin marshalling about 15 minutes ahead of schedule.

OB

Be aware that individual events are often re-ordered within a session. There are two primary constraints that drive this - the first is that the largest event will require the most rounds, so it is run first. The other is the minimum time (usually 20-30 minutes) allowable between rounds of the same event, which usually prompts interleaving of age categories in addition to levels. By the second round, the order can be all mixed up.

A good MC will usually tell you what event is going to be run after the current one, but not always. If they start the latin 5-dance, you generally know you have a 6-7 minute safe window to visit the restroom before they can call anything else, though I suppose there are reasons (temporary injury?) they might stop in the middle and run something else instead.

Also, if a time is published, they are allowed to run an event up to a half hour earlier than that.