In general registration opens in the second week of July, after the fees have been finalised.
Rules for the timing and the composition of the jury are explained here
Check the rules here under "For the supervisors"
Yes, no problem. It would be good, however, to get a letter of appreciation from the responsible for your Masters programme to include in your application documents.
In such a case, please ask the reviewer to send an email to Jacqui Shykoff and Marianne Delarue for the 21 days before the defence at the latest, stating that the thesis is of a quality to be defended. The full rapport can arrive a bit later. With this email we can sign the documents that authorise the defence
The thesis subjects are posted on line each year in mid-March. The competition takes place in the last week of June. You can find the rules for the competition here.