Well I don't know how to queue files within a torrent but I quote form another source:
That this is a bad idea is an understatement. If you don't understand why,
then you don't really understand how torrents work so it might be
difficult to explain, but imagine when you're doing your grocery
shopping and have 100 items on your list, so you walk every single aisle
in the store until you get to the milk, because it's #1 on your list.
You just passed bread, vegetables, fruit, cereal, frozen foods and got
none of it even though you know you needed it because you've decided
it's a better idea to get them in order. Now that you've got your milk,
next is coffee, so you start at the beginning and walk every aisle
again until you get coffee.
If you ask me whether the priority feature for files must also be a bad idea then I would say no. Priority works differently than queuing. When you set a file to high priority, it will be downloaded ahead of the files with lower priority, given that pieces are available for both. But if the pieces for a high priority file are not available, compared to a low priority file, it will download the low priority file.