All changes regarding teams are downloaded from the registration web site each each time you enter the window "Participants" (and also when you activate a tournament).
You can only change name on teams in your admin site (not inside TXO)
If a team is deleted on web, and the team has matches, the matches are NOT deleted but will get a vacant team as a replacer. This is in case you will get another team to replace the deleted team. Matches with vacant teams are shown with a light blue rectangle.
When you active the tournament the first time, all teams are downloaded from the registration site, and assigned into group A in the category.