lol..wow that is a lot of questions but very easy to answer :). So I would bring with you anything you need to repair your piece if anything happens in transport. Kind of like a repair kit you would bring for a real cake.
Judges in the competition I have been too look for cleanliness, color, intreptation of theme, originality.
Again at the shows I have gone to they give you time the night before and a few hours before the show starts to set up your piece so you can assembly on site if you wish. No they do not cut into cakes that are not being entered into a tasting category.
You can squally bring anything you like to present your cake. That includes stands. Just keep in mind that there usually is no electricity by the show tables. For me it has benn assigned spots and not first come first serve but this all depends on how the show is run. I would assume that if the show mentions size restrictions they are going to give you a spot.
I hope this helps answer your questions.
