5* is best.
10 minute matches make the whole tournament take a while but most would agree that this is the best time for a match. 5 minute matches are bad as they are just a race to see who can win 1-0 most of the time.
Usually you get the choice of national or clubs teams. Then let everyone choose whichever team they like. Or get them to bring their own Master League team (loaded on the Default settings so that if they've changed the stats it won't matter and everyone will play with the default player stats).
You can draw teams out of a hat in a world cup style and seed the groups according to player ability or the quality of the team. But people usually need time to practice with new teams so maybe pick the groups a couple of weeks before the event.
National teams is the most common choice.
Fairest option is to use no option file when loading the game. Unless everyone uses the same edited option file. I don't like playing with the default kits but playing on edited files gets you used to adjusted stats too. Maybe someone should create a good option file where only the kits and club transfers have been updated and not the stats.
Kent is quite cool
I went to Bluewater on Bank Holiday Monday. Good day